Bad service

I have received bad service from cell c ever since I have taken out a contract with them ...endless issues. My number in question had been handed over in 2014/2015 to the attorneys which I had paid and sent proof of payment to cell c and to the attorneys SHAPIRO SHEIKH and now all of a sudden i am unable to check my airtime balance or even make or receive calls and when I called cell c they tell me my account was handed over for not making payments. This is so uncalled for as this was my very first contract taken with cell c and that was paid off in full and asked to cancelled which they hadn't done clearly cause after a few years later my account has still been handed over for what reason cause clearly someone hasn't been doing their job. I'm so angry that I would never recommend cell c to anyone this is such poor service.. I have even called the call center and they told me that this account had been closed On their side. So how can my act be handed over after a few years.