What customer service?

Firstly, MTN forgot to load my data, after I was asked 3 times to call back because of "systems are slow" (not good advertising for a cellular company) I asked for the manager Sibongiso Nobuwo to call me back but this never happened. I called back and a gentlemen told me that my data will be sorted by Monday, some of it was. I got a a message from MTN that states that they did not give me enough time on the 10GB x 3 months and they will add the last 10GB this month, its the 13th today and nothing yet. I called again and after Portia Maimae couldn't assist any further, she gave me the excuse that my line is getting bad and I need to call back again. This is absolutely the most pathetic service I ever received. I will now stop my debit order until this is sorted out, I will not pay for a service that is not given to me, you are more than welcome to arrange for my phone to be collected and end my contract.