Cell C terrible service and communication

Cell C has handed me over for an account which ended over a year ago. Nobody at their call centre can tell me what is going on, the company phoning me for the amount is a different person with a different amount every day and the Cell C legal department is not available due to a technical error. I can't get any answer re why I never received any invoices or statements and why they didn't debit my account for so long if apparently the contract was still active. The legal company calling told me that there is no legal department that I can go to and as I mentioned can't call them either. When I asked them to get Cell C to call me they sometimes say ok and sometimes that Cell C will not call me.