MTN SA NO HANDSET OR SERVICE BUT TAKING MY DEBIT EVERY MONTH!!!!!

I am appalled and very disappointed with the service I've been receiving from MTN SA for the last four (4) months. It all started when I decided to upgrade my contract, I then took out a Samsung A6+ it was delivered to my home address on 24 Dec 2018, end of January 2019 I could no longer use the handset as it was turning out to be faulty, screen was changing to all sorts of colours and immediately I took it back to one of the branches where they booked it in for repairs or replacement if possible by then it didn't really matter cause I needed my handset for business purposes. A week later I was contacted to collect my faulty handset as MTN SA is refusing to repair or replace it due to negligence which according to my knowledge was incorrect never has this handset fell or anything it was literally brand new and 3 weeks old. I then contacted MTN SA again and was then advised to return the handset again and that they will replace it. MTN SA does not follow up or update me with how far the investigation/process is, it is now MAY 2019 my debit is still going off every month my sim card has not been in use since 30 January 2019, I have no handset I am still paying faithfully yet no handset No apology nothing I spend hours on the phone trying to get answers but none whatsoever, no call backs I'm being transferred from one department to another. MTN SA is guilty of theft *****ing my money without me being in possession of their property. I am pursuing action from ombudsman.