MTN LACK OF SERVICE

MTN head office service is SHOCKING. I deal with our company cellphones and when calling the head office you end up holding for nothing less than 15 minutes (if you are lucky) or the call just cuts. When yo send an e-mail you get get a response saying the call has been logged and someone will get back you shortly - clearly my definition of shortly and MTN's definition are very different. I have been trying to organise virtual; SIM cards for our Directors, got the standard mail of someone will get back to you shortly on 5th May 2021, surprise surprise I am still waiting!!!!!! Been into 2 MTN stores to try and organise these but the store staff are not able to assist - HOW DO I GET THIS RESOLVED?????