MTN is a *****

I have two contracts with MTN and upgraded one of them on 01 Nov 2023 and took a multi device deal. The deal included free airtime and 3gb data on the third device which came with a Sim card. There was no cancelation amount charged since I upgraded a month before my contract ended. Now MTN is over billing me. Instead of debiting R915, they are debiting me R1128. Raised this with them and they advised that they erroneously charged for the free device and will fix the problem. To date, nothing has been fixed. Then I raised another issue that I was not being credited the 3gb as per their Nov catalogue and now am being told that I must raise he matter at the store where I upgraded. What a lot of ****, why are these incidents being isolated? My money is not being debited in isolation. Why are they able to fix the billing and not able to fix the data mess? MTN is a ***** on its own. Always have bad experience with them. Acting like they are doing customers a favour when we are the ones bringing in business.