How do I file a complaint about horrible, incompetent and negligent customer service?

Question

I might sound super rambling but I am very frustrated and just tired of explaining the situation over and over and over.
On Wednesday, January 21st, I got a call from Verizon Loyalty Department about a "promotion", which I get $25 credit on each line if I upgrade with edge plan. I wasn't sure what phone to change, so I asked them to call me back on Friday. They called me on Thursday, but I couldn't get the call, so I called them on Friday and talked to the customer service. I wasn't still sure about the upgrades, so I asked them about the upgrades with $25 credit would still apply several weeks later if I decide to upgrade, the first representative whom I've talked to looked at my plan and said something like, "Yes, that is absolutely possible. I was looking through your plan, and since you are a loyal customer and ended your 2 year contract with us, I can give you $25 off on your each line. I asked them would I still get the $25 credit for each line when I upgrade to edge plan. He said yes because the $25 off that he is giving me is for the monthly charge and the edge plan $25 credit was for the equipment charges. So Month to Month $25 off was applied on the Jan 24th, and activated on 29th.
After I finally decided to upgrade my phone, I called Verizon customer service the next week. I do not recall the exact day but on 28th or 29th I called to upgrade it, and the second representative also assured me that the credits were going to happen, and then he offered me to bump down my data to 6 gb from 8 gb to save money because I use less then 6 gb each month. I bumped down to 6gb loyalty plan so I was only paying $60 per month instead of $70 per month. The representative told me I would be only paying around $120 per month. I forgot to ask my sister what phone she wanted to change, so I didn't upgrade it right a way. So only the data plan changed on that day.
I was extremely busy with my work for few weeks, and I finally called again to upgrade it, the third representative told me different old me that the previous representative was wrong about giving me another $25 credit when I upgrade with edge plan. So I ended up upgrading both of my lines with $25 credit on each line plus $60 for 6gb data. But she said I would be still paying less then what I normally pay, which is around $183. I upgraded and took me few days to receive my phone. I checked my bill and it was showing different than what I was told. I called again and explain all this thing again and the lady adjusted my data plan - 6gb loyalty plan for $50. She said she doesn't know what other representative was doing, but this will fix that I would only pay around $150-160 per month.  After I got my phone, I called verizon to activate my phone (I don't really remember it was before or after, I just talked to them too many times and they have changed my promotions and plans too many times in very short time). He also confirmed $25 credit off for each line, but there was one time tax fee that none of the representative has mentioned while I asked bunch of questions about the upgrading fee and how much it would cost on the first month and etc.)
After all of that happened, I was settled and didn't think about the payment until I got $290 with only $15 credit on my bill. I called again and asked what happened and the representative told me she doesn't know why this happened and why the previous representatives told you something that weren't true. and I had to go through the explanation again. She said she fixed it and everything was taken care of.
I checked my bill today. My plan was changed to $90 for 6gb and I was paying $30 more than I originally paying which was around $180 and $50 more than I was supposed to pay. I called the representative today, explained the previous situation and asked why this happened. Basically he told me that all the previous representatives were lying to me. Are you kidding me? They were lying to me? How am I suppose to know if he wasn't "lying" to me? He said only thing he can do is change back to my original plan and amount, and I would pay $6 more than what I used to pay which was about $183.. I asked me if I would get the the 8gb back. He told me that isn't possible. The change did not happen so far. I am tired of calling verizon and more tired of getting different answers from different representative.
I am seriously concerning about changing my service to different carrier. I have to call the verizon every single month when there is a change in my plan. If they were really lying about the promotion and plan just to sell more service, they should be suspended or fired or something, and I need my money back for overcharged fee and need some kind of compensation for my wasted time and stress I got from this.

Answer 1

Okay. You are just missing the whole point, and I am not saying anything after this. I did go to the website to read about the edge plan after I got a call from the loyalty department. I asked the questions on some parts I didn't understand (or was confused of) to the representatives. But my main question was whether I was getting $25 credit and in what conditions. They all answered differently to the same question. (My original question - Do I get the $25 credit with edge plan?- One rep. offered me that month to month $25 off before my upgrade. Other rep. confirmed $25 off plus $25 credit with edge and offered bumping down data plan to save extra money. Another rep denied $25 off plus $25 credit with edge but confirmed decrease in my monthly payment by bumping down the data plan. Other rep denied both. You see what I am talking about? I asked one question to begin with: am I getting the $25 credit with edge upgrade plan - and they are the one who offered me different promotions and offers) 
I also left the part that I actually went to the website and 'researched' the different plans that all the representatives were talking about after I hung up on the phone each time. I joined the forum today because I wanted to know where and how I could file the complaints on verizon customer service after today's call. I should have been more clear on what I was asking, but I thought I was clear enough on my title "How do I file a complaint...?"  Yes I am angry at the fact I didn't get what I thought I was getting, but I am more frustrated the fact every single time I talked to the customer service I get an answer from the rep. I am on the phone, saying "Previous representative you've talked were wrong about this," or "They were lying." The representative, then, would fix my issue, but I would still get the conflicted bills. Don't I suppose to call the customer service to fix it? What's the customer service for if it's not for that?