Cannot be trusted to do the right thing

MTN probably doesn't even care about me as a client and my experiences, but I am sharing this in the hope that it saves someone. I had a 24-month contract with them. I paid the instalments faithfully without missing a single payment during that time. A month before my contract expired, I gave notice as required. They still charged me a device cancellation fee even though the contract says ownership will be transferred for free when the contract expires, if I did everything correctly. I did this and more and still got charged.I gave them all the chances to fix it, and they didn't. Now I am left with no choice but to reverse my money and block them from my account.