MTn are Absolute ******s

Been with mtn for several years always renewing my contract until this year. I decided after my last contract there weren't anything worth my while and retentions didn't even make an effort to offer a deal to keep me. I decided to cancel my contract after it's 3 yr period. Gave my notice and then switch to prepaid. 2 weeks after prepaid I got debited. Thought it was my last. September month came, another full debit. Bear in mind I received none of the benefits of my contract and still got charged the full amount. October 1st I called contract department. Argued my case was told invoice issued a day before cancelation. I insisted as this can't be right as I gave my notice period and you can't still be charging a full month service for benefits I don't have and still pay the device fees. I asked for a dispute to be logged. Was actually a complaint but agent turned it into a dispute. Said 24/72 for a follow up. It's 0ctober 4th 21h47. Still no follow up. I'm so disgusted. Will be talking to my bank in the am to reverse the debit then they can call after me for a change. 🤒