Sim swap - poor customer experience

I'm an afrihost customer with an MTN sim card and I've BEEN trying to get a sim swap from a micro-sim phone to a nano-sim phone. Afrihost told me that once I've bought a nano-sim I need to call them for assistance, which I did, but every time I call the contact center, their agents put me on hold forever, only for them not to be able to assist or even drop the call. I then called MTN's '135' and was told that since I'm a contract customer I need to speak to Afrihost., but they had proved useless. So I decided to go to an MTN shop for assistance but they also couldn't help me. I'm at the point where I just want to cancel the damn thing because clearly no one cares or is able/willing to assist and it seems no one knows who is supposed to assist.