Bad service from Cell C

I had 2 phone contracts with Cell C. I settled both contracts just to find they have listed me with the Credit bureau for an account in arrears. The amount I paid off on the contracts was +- R24000. They listed me for an amount of R1214. 22 for which neither Cell C nor the debt collecting agents know what the amount is for. Phoned Cell C numerous times to enquire and they informed me everything is paid in full and no outstanding amounts. Then I paid this amount and asked them if they can send a notification to the Credit bureau to inform them the amount was settled. They informed me they can not do that and that I need to do it myself! What pathetic service as I have been a customer with them for years. Will definitely not ever support them again!