Wrongful billed s result of an *********** person

MTN is frustrating me, I had 2 contracts with them and the one I m calling them with is the one that I wanted to upgrade them the other one I bought for someone , I wanted to upgrade my 073025 no then they upgraded the wrong number , then 15 November 2020 they debited then I phoned asking why have they debited cos I have not received my data (upgrade package) then only to findout that it loaded on the wrong number then they said they will cancel that no since I m not even using it n they wil not give charge me cancellation fee for that contract cos it was supposed to be ending on the 8 December so that one was resolved/. Now I want to upgrade my 073025 I can’t cos their system is saying I m owing 350 that I don’t know cos the last time they debited was November 15 they even debited for the package tat I did not receive so they said they will refund me but it will take 21 working days and the bill section my reverse or cancell this 350 as it’s blocking me to upgrade n it will take 5 working days but it’s been more than two weeks now they have not cancelled the 350 which means they will debit again on the 15 th I have been given may references 1-***,***, ***, ***,1-***. I have many but till today this issue is not resolved