Telkom Disgusting quality of service

Would like to know who can I contact to escalate an issue with Telkom. I have two contracts with Telkom, every month for the last 3 months Telkom suspends my account stating credit limit exceeded. There is no monies outstanding, the call centre agents keep saying the same thing with no resolution. I am at my wits end, there is no one internally at Telkom to escalate the issue to. I need to end the contract, i obviously need to pay the devise off,or get lasting resolution. The customer service is absolutely atrocious, the Telkom store is of no help. The lack of knowledge among the staff is absolutely disgusting.