Please HELP

I have been having problems with my account since February 2015 two moths after I did an upgrade even, I was incorrectly billed and even though I was promised that the credit will be passed on my account but the account was still left with the huge outstanding amount, I did make an arrangement to payment this amount and I have paid last month and I was also waiting to pay for this month on the 25th and now my line has been suspended i have been told that my account has been handed over to legal and i have been give three different contact number to contact the legal department and when i phone there i get told different stories someone told me that they can't see my details on the system, and someone told me that the legal does not take calls and the moment and they will only get back at me after two day, it really frustrating because I want to resolve this but it seems as if no one is willing to have or explain the way forward and in the mean time I CANNOT RECEIVE OR MAKE ANY CALLS