Non-stop debits from MTN South Africa cellphone contract

I have purchased an iPhone with MTN South Africa. It was a full 3-years contract and it ended on the 20th of January 2026. I went to their branch to inform them to cancel everything so that next month (February) it doesn’t debit. They redirected me to call their customer service number and I did I requested for a cancellation and it was done. Surprisingly, on February they debited and when I went to the bank to dispute it I was told that it was undisputed. Last week I received their bill invoice stating that they’re still to debit this month (March) again. When is this ***** ending? Why are we being ****** our hard earned monies? My sin was to open a contract with MTN? Am I suppose to pay till I die? No! This needs to stop! I resent the day I walked to that MTN selfish store ever!