MTN no connection- Poor service- Money lost! Do not use MTN.

I am on your network for the last year and I am very disappointed having moved from Vodacom. I have called your call center 4 times to get assistance with my sim cards not picking up and having to switch my phone off and on in order to make calls. This is now affecting my work as my clients cannot reach me. I need my contract cancelled with immediate effect so I can move onto a service provider that actually works!