MTN poor performance

I have received 100 minutes and 1 Gig of data short on one of my contract for 4 months in a row now. I contacted MTN 3 times now and keep getting told they will escalate it again. Today on ref no *** I was told it takes 3 to 5 working days to resolve so I reminded the employee that it is now 3 weeks from the 28th July which is 15 Days since my last call. The "service champion" informed me that it is the customers responsibility to follow up with them 3 to 5 working days later and I have left it too long. I am shocked MTN expect their customers to remind their staff to do their own jobs and don't have their own follow up procedure in place. I am concerned they did not let me know the outcome of the previous escalation. I am upset that I need to make the same call every month to be ignored by MTN and its so called "service champions" the only thing MTN never neglects to do is take the money from my bank account to pay for a service i am not receiving in full! This complaint is to ensure MTN do follow up and escalate this issue themselves and hopefully offer other customers a better experience!