Data Contract

I'm using MTN number since 2009 and it was a prepaid number till February 2020 then I bought a data contract from MTN in February 2020... Unfortunately I lost my phone in end of April 2020 I went to MTN store to do sim swop fist of all that sim card took a month to activate sim card which is totally waist of time then since ever I'm unable to make outgoing calls and I'm unable to use data. I try to call on MTN help line more then 10 times and I wen to different MTN Store but they are all waisting my time and no body is able to help me I'm so disappointed from MTN.. They are ***** bcz they have been deducting money from my account while I'm unable to use their data service which they have provided in my Contract... It's a 24 months contract and I'm totally stuck with them dnt know what to do if I stop paying them then they will put me through legal department.. It's my humble request plz take a strict action again MTN.. Bcz it's been 3 months I'm struggling to make things right but no body is able to help me.. Their staff at cape road branch in Port Elizabeth is totally useless...