Cell C and Nimble Group failing to solve my case with their supervisor (Haneefa Adams)

I had a cell c contract that was handed over to Nimble group, i paid the account and even paid them R300 more which was never credited back to me. Now Nimble group does not want to remove my name from their system they say Cell C needs to send them confirmation, even after i have presented all the necessary proof of payments. when i contact Cell c they say they are unable to assist me because the account was handed over.....My name is being tarnished because of these two *********** companies who's failing to solve my case.