I am no longer a Sprint customer. I was for almost **-yrs.*acct...

I am no longer a Sprint customer. I was for almost **-yrs.*acct * ********* * ***-***-*****Back April or May my iphone * began not working properly. Very bad for my business. My business depends on my cell phone **-*. Went to the Sprint store where i purchased the phone, about a year ago, asking for help. They reset the phone & dismissed me. Spent many subsequent hours there while they put my phone on a diagnostic machine. Was told there was nothing wrong. My clients could not hear me, "too much static". Kept having to go to a land line to return calls. Was told to upgrade to a **. No improvement. Finally was forced to switch providers to get a phone that worked.*A refund & an apology would have been nice. Instead Sprint continues to send me bills! Latest bill is $***.**! Have called several times but nobody has any authority to help. Keep being told a supervisor will call me . NEVER has anyone called.*Please tell me who to contact for help.*Thank You-Edna Core