MTN Terrible Service

My son changed from cell c to mtn over a year ago, since this change he can't received sms messages on his phone from other service providers besides mtn, he also doesn't receive messages from his bank when making payments.

He has gone to numerous mtn stores and they have provided him a code which hasn't worked, he again went today and it shoes on the system that the messages are enabled so he decided to do a sim swap and after that it still doesn't work, this time however it gives him the error code of WIB error 34XX which we don't know what this is for.

This is extremely frustrating is no one is helping him and the customer care call centre keeps saying it should work but it doesn't and even in the stores no one knows what the issue is, originally other providers he didn't receive calls as well and this seems to be now working but the sms messages are not being received, please we need urgent assistance from someone who can call him and sort this out finally.