Bad service

So I've been with MTN since 2019. I'm on my 3rd cellphone contract with them. Never had a problem until early this year. I renewed my contract late last year and for the first 3 months I paid the agreed upon amount. Then out of nowhere I start noticing additional deductions from MTN. At first I pay no mind to it but then it became a recurring payment. So I go into their branch in Robertson and the consultant there tells me that the deduction does not show up on their system and that I should call in to find out about it. Fast forward a few months, I'm on a call with MTN and I enquire about this random deduction. The consultant tells me that the about is deducted to cover VAT and a billing fee. I have never heard of a contract where the vat is excluded from the contract amount and is paid for seperate. I explained to the consultant that it's not that they have been deducting these amounts since the beginning of my contract. It's something that started a few months after the start of the contract. I have never received any billing from MTN yet they are charging me for that as well. She informs me that she will escalate the matter and that MTN will get back to me. So once again they deduct this amount and I decided to reverse the payment until I get answers and until I know what I'm paying for, as this was never disclosed. A week after reversing the payment, MTN sends me an sms to inform me that they have blocked all outgoing calls due to non payment. The contract I have with them is one that gives me more minutes than data (because I make more calls).

On the other hand my wife missed payments on her contract. Fast forward a few months she goes to reapply for a contract and they tell her they cannot help her as she is blacklisted by MTN. She pays the outstanding balance and a fee to have the blacklist lifted. Months have gone by and they still haven't lifted the blacklist and refuse to help her with a contract