VVM unduly blacklists customer with CellC account which is under dispute

I had a previous account with CellC and cancelled the contract. After a number of months I received notification that there was an outstanding amount that was handed over to VVM for collection. I followed up on the matter but VVM referred me back to CellC. After numerous calls CellC could not provide details linking the outstanding amount to my old account. I established that VVM has proceeded to blacklist me due to this amount which is under dispute. Both VVM and CellC have acted in bad faith or display huge incompetence. I am lodging this matter at ICASA.