Cell C nightmare

On the 30th of April my cell c debit order went of at the bank as usual. A few days later I got a sms stating that my account was overdue and another stating that my credit card had expired. I contacted the cell c sevice centre, were advised to check with the bank and then follow the steps send to me by sms. I checked with the bank, who confirmed that payment was made, the sms from cell c however was never recieved. Phoned to change the expiration date(which had to be done for the May onwards, not the April debit), were informed the cell c system does not accept the month indicated on the the card and I should visit a cell c store, I did visit the store, credit card in hand, and after some effort they said the system indicate that it was changed. I also phoned and send an email regarding the unallocated 30 April payment. End of May, same smses ... credit card expired, account overdue (now by 2 months), this was followed by a "your account has remains suspended with a negative credit listing". I made an IIP payment, paying for april (again), may, june (in advance) plus extra to have a credit on the account, which was allocated by cell c on the 11th of june, showing the account to have a credit. On the 12th I recieved an email stating all kinds of hell if I don't pay within 7 days. Phoned the service centre, who confirmed the account was not in arrears. Now a bit upset I send another email to cancel the account, which has techincally ended months ago, stating the 30 April issue as 1 of the reasons. 3 days later I recieved an sms to say my cell c account is now being managed by Nimble. I phoned the number in the sms and were told the account is not in arrears. I asked for confirmation, but was told no they can't give that. Every day thereafter I am being phoned by Nimble/Cell C to collect. Can someone at Cell C, please attend to this matter, I have done everything in my power to ensure that there is no reason for cell c to continue with this ... I don't even know what to call it. Any assisance will be appreciated.