Iphone 4 constantly dropping calls or "call failed"

Question

I've been having nothing but trouble the past couple weeks with dropping calls or getting the "failed call" showing up when trying to make a call. It happens more times than not and i spoke with Apple today and was told that after you try all the resets and restore options it should be fine. If that doesn't work, its more than likely a SIM card issue and needs to be cleaned or replaced. I did all the restore and backup and all the other garbage they advised me to do, and still did not work. Took the SIM card out and im not sure if its supposed to sparkle in the light, but its pretty **** clean. Re-inserted it, and still dropping calls or "call failed". Next option is getting a new SIM card tomorrow and i'll update what i find out.
Previously, in July, some moron from Canada was beaking how its a service issue and he's on Rogers network, blah blah blah and he's never dropped a call and its superior to AT-T and mentioned something about how all the ppl would have no trouble if they were on the Rogers network.
Well i'm from Canada and work with 2 other ppl, surprise, from Canada who are having the same problem with the iphone 4........its not a network thing whatsoever, because ppl on Telus and Rogers are having the same problem. Im assuming he was from Toronto where the center of the universe is and he was basically just being an idiot, so for that moron, i apologize to ALL who are having issues with the iphone 4 and hopefully Apple gets their act together and solves this issue!!

Answer 1

Hey everyone, I think I finally got the solution for this. It appears to be a NETWORK ISSUE with the phone provider. I am a Telus subscriber and after speaking to a cool tech guy from Calgary named "Corey", he performed the following task:
He told me he had to reset 4 settings on the network for my account. A few of which were under something called "STF viewer" "PLMN" and "PRL"...
Aftewards, I had to go to my iphone: General > Reset > Reset network settings
I am now able to complete phone calls (and apparently my reception sounds better to my call recipients/callers too). The problems is not related to a "faulty device" or "something" you did... If the problem happens again, I'll call my provider and have them investigate the ticket further as it could be a bigger network issue (with GSM) but chances are it just requires a simply settings reset on the backend of your provider's data support team.
After doing the reset, all I had to do was reconfigure my wifi password. No other settings were lost. (and more importantly, I didn't have to re-restore my iphone, didn't have to go to Apple and sound like one of those "iPhone 4 vs HTC cartoon characters" and didn't have to yell like a child to anyone. Just be cool when you call your provider's tech people, these guys are good hard working people and will help you and will have a better chance at success if they empathize with you and don't feel annoyed by you (I'm in IT, I know how it is).
I was also told that if I had to call back and if they had to reinvestigate, the next steps would probably involve having my SIM card changed but based on the previous tech's experience, it would be highly unlikely. I will update you further should I encounter any further issues. Just don't be hating on the iPhone 4 as most people do coz it is a sweet device if you can understand the tech specs behind the underlying issues.
Hope this helps you guys and anyone else who got frustrated by this problem!