Breach of debit order agreement and incorrect listing

From the date of taking up a contract with Vodacom I agreed to be debited on the 20th of each month yet the past few months they dont debit and I have to either pay via eft and now I see they have listed me for something that is their mistake and I have been telling the consultants that called to reinstate my debit order.

I'm done with Vodacom and after this contract I'm not taking anything again. The only reason I upgraded was because my first contract went well and was debited on time as I had agreed but this one is seriously getting on my nerves.