MTN SA: No1 DISAPPOINTERS

MTN has disappointed me, after being their loyal customer for quite some time. I have a data sim card contract with them and last month I received data but couldn't have access to the loaded data because the sim card has no interest access. I tried to call customer agents so as to solve the issue they were defeated. They even suggested that since they can't solve the issue I must go to MTN direct store in Sandton, I've done that and there was no sufficient help. They suggested that I must go to the store in Morningside where I can find a technician, I went there and found no help up until this date. As we speak they have they have billed me for the data that I didn't have access to and I highly doubt that I signed up for that one. I even suggested that they should cancel the contract because they can't seem to find the solution around the problem, as I won't pay for data I didn't have access to. They didn't do that. They said I must settle the outstanding balance and pay the cancelation fee, of which I won't do that because if the sim had no network issues, I wouldn't have opted to cancel the contract. I'm so frustrated because my life is stuck and this will ruin my credit score if they don't resolve the issue or if the issue seem to be unresolved, they cancel the contract once.