MTN Contract Upgrade

I upgraded my contract on 6.10.2020, only to be told that the sim card cannot be used in an IPad only in the router and was told bring the router back and they will cancel the upgrade and revert my contract back to the original, this was done 6 weeks ago, MTN Northgate cannot give me an RMA number and SME Cancellations won't cancel the upgrade without it, I am beyond irritated and frustrated with MTN, it is the most despicable, unprofessional and disgusting customer service i have ever received from MTN.