Mtn worst service ever

Took a contract with MTN month end July for 40GB of data that's supposed to deduct R199 per month, for the first premium deducted on the 1st of September so they deducted R454 and when I enquired they said its pro rata and I was told they overcharged me but they won't refund me in cash instead they said they will add it to my mtn account of which I don't understand cause it's their mistake, why should I be the one sufferin??? Fast forward to this month they deducted R300 and I called their call center they told me they won't assist me without the agreement, which I was never given at the branch where I took the contract. Mind you I am from Butterworth and in my town there isn't a MTN branch, the closest town is East London which is 110km. I asked the lady assisting me on the phone if they can't they request the agreement from the branch and they said No. So I had to drive to and from only to get to the branch to find out that the lady who was assisting me was not at work on that day, when I asked them if why can't they login to my profile and print the contract for me they said NO again saying they can't access the lady's computer and she is not at work for the day. Left my number, was told the lady by the name of Sipokazi will call me when she gets to work the following day. I Waited and waited, I never received a call from mtn or the lady who was assisting me. So today I drove once again to get feedback only to find out nothing has been escalated. I am so frustrated and disappointed in their service. I regret taking up a contract with mtn