Service is a rare commodity

Went to Westgate branch to find out how to cancel a contract that was moved to my Mothers name from my late Father. Got looked at as if they got shined with a bright light or something, after a while I get told that I must send a message on the online portal (please note they unable to help with this in store)

Then when you do it on your own account after wasting you time at the store, you get a mail back from MTN saying the mailbox is full and cannot accept the mail.

So the goal is simple, someone that actually know how MTN works, just let me know how do I cancel the contract for my Mother and then if there is costs involved what is it and why, basically a breakdown.