customer care that have no answers

I had a contract with cell c which was a cell phone and data, earlier in February I called the customer centre asking them how much is due to them when I leave the contract and fully paying the my obligations an amount f about R1700 was paid by me to cell c to cancel the contract with after paying the amount contact the customer care to cancel the contract and the number which I told them I don't even want to keep their number under no conditions which it was terminated according to the conversation we had with the customer care rep, to my surprise 31/03/18 I get a debit order of R113 which to cell c today I call the customer care I was transferred from one person to another eventually the last stop was a department called the pre legal, where no one is answering the phone because no one has answers for me concerning this debit order.