MTN is useless, stay away

MTN provides terrible customer service. MTN is the worst, their customer care consultants useless and everyone generally ***********. I took out a contract with MTN in march for a Huawei P40 lite, when the device arrived it did want to take 2 sim cards. I realized that maybe it just did not work with 2 sim cards, even though its a dual sim phone, so i decided to return the phone and cancel the contract. The day after I received the phone I took it to the nearest MTN store and returned the device, I told them I was cancelling the contract but they told me that I had to cancel it with the online agents since I took the contract with them. they gave me a reference number for returning the device and i left. I contacted the online sales agents for MTN told them I was cancelling the contract, gave then the reference number and thought i was done. A month later I received a statement from MTN saying I owed them, I quickly responded to them by email and a few days later they sent another statement with no amount owing. Another month later I got a statement which said I owed R8000, they debited the amount from my account but I reversed the transaction ,at a cost to me. this time I called them and they assured me everything would be sorted out. Today the 1st of july they have debited R8000 again which I can not reverse even though 3 days ago I was on the phone with them the whole day to resolve their billing issue and they acknowledged that the error is from their side where their employees did not do their jobs correctly. Stay away from MTN