*********** to resolve a simple query

I have been trying for weeks for Cell C to sort out my debit order not going through, The error is with Cell C and they need to correct. Every week is a promise that it is going off the next Monday. Again this week did it did not go off. The worse part of it all is, Cell C collections department phone me because I am not paying my account! How crazy is this!. This is really terrible service and I do not know who to get involved to get this sorted out!