Not able to make outgoing calls - MTN South Africa

I have an issue with my MTN line. I can not make outgoing calls. I have phoned the MTN Customerservice line 2 x times. I have been to my local MTN shop in Klerksdorp, Flamwood 2 x times. I have even left my sim card with them, but up until now, not even they have been able to resolve the issue. It has been 6 x full days now, without MTN being able to sort out the issue. Seems like my only option will be to cancel my contact with MTN and move over to a different provider. One would think that taking into consideration the current strain on global economies that Customer service would be a higher priority.