My iphone 4 just stopped receiving or making calls. I have tried everything! Help!!!

Question

Okay, one day a little less than a MONTH ago, my iphone 4 just stopped receiving calls(90% of the time) and making calls(50% of the time.).  I panicked because my job depends on my phone to work.  So, i go to apple, ATT, back to apple, back to ATT, etc.  There is no end to this.  And, literally, the people at ATT and Apple, keep telling me that they are probably not going to figure out a solution, and that I should just cancel my account.  Now, I really don't want to do this!!!!!!!!!!!!!!!!!New iphone from apple because they thought it was a ATT problem but gave me new iphone 4 anyway, new sim about 1 minute after the new phone, new phone number. The engineers at ATT said if i relocated and told them that i was moving, it would give me a new number and reset all the routing stuff.  I didn't want to do this because of losing my number with business, but had to resort to it anyway.  Now I have a number from a different state, and I still have the problem!!!!!!!!! I have exhausted all my options with apple and att, and both tell me the only thing i can do is buy a prepaid phone from a different service!  I need my iphone for work, and this has been going on for over a month now.  I was told there was a routing issue, but the engineers opened a ticket on it, and NO solution.  Then they opened a second case ticket, and still no good.  They are claiming I should cancel and buy a new phone.  My phone just stopped recieving calls one day.  No notification of missed calls, EVER since this started happening.  Voicemails go thru( only some of them) about an hour or two later, and texts are taking a bit longer than usual.  I have really tried everything the engineers can think of, even getting a brand new phone!  Please someone help me!!!!!!!! I am desperate!!!!!!!!!!!!  This happens anywhere i go, not just in my area.

Answer 1

Might sound silly but is the mute switch on the left side of the phone in the correct position?