Cellc does not know who they have handed me over to or why!

I had a cellc contract about 3 or 4 years ago. To my knowledge it was paid up. I have not received any calls to inform me that I have been handed over. While doing a credit score it picked up that I am blacklisted because of this cellc contract. I have been to the cellc store at Midlands Liberty Mall, Pietermaritzburg and they asked me to buy a cellc Sim card to phone customer care and ask them how to make payment as nothing shows unpaid on their system and they do not know which account number I should make payment to. They don't even know who they have handed me over to. So I called cellc customer care and they too, don't know know who I've been handed over to as it shows that I only have a prepaid number on the system. After the back and forth process, I was then asked to call a few companies to check who I have been handed over with. And until today there is still no joy. This is ridiculous. All I'm asking for is an account number to make payment so that my name is clear, and cellc cannot help me with this! I would appreciate it if someone gave me a call on *** regarding this matter