Worst Service Provider EVER!!!!

in June, i have decided to take out an additional contract with MTN. a simple request has caused severe frustration as it is now 2 months later and i am still waiting for a sim swop to be done. i am being given the run around as each and every person i speak to gives me a different answer. I also opted to upgrade my existing contract early and was told that an additional R900 would be added to my account, which now - i see my account has been debited with R3000. i have gone into mtn stores, phoned several times, asked to speak to a manager, was told that i would be called back within 24hours. Up until today, no sim swop and no further feedback. Even when i request a statement on their app, i never receive it - so i cannot even see where this additional R3000 came from?! in all fairness, MTN, if i have to wait so long to get any sort of service out of you, you can be assured you will be waiting to get payment from me.