Appalling service received by MTN

I am extremely disappointed with the service received at MTN. I requested a cancellation on my data contract on 2 December at the Rosebank mall branch however ‘this request was not actioned resulting in me being charged for this contract in January. I queried this at the branch and was helped by the manager claud who advised that he will process a refund to me. I get a call today from claud advising that the refund could not be processed because the data was allocated and used by myself in December. Firstly I find this very hard to believe as I was away on holiday overseas for most of the month. Secondly if my request was actioned accordingly in the first place we would not be having this argument. Thirdly I have fibre in my home hence I’m cancelling this contract because the signal received from mtn is awful. Claud expects me to call the call center and speak to the necessary people to see if they can assist me. What’s the point of having a walk in branch if I still need to find my own way to resolve my issue. The service received is appalling with no intention to help at all knowing the fault is with the service provider. mTn refuses to take any accountability or responsibility for not doing their job right the first time.