MTN contracts and their service is a mess

If you want a phone contract, don't ever go with MTN Contracts, what a nightmare.I bought a phone on a contract which was on promotion with them 2017, my contract is supposed to end this year 2019 in October and all of a sudden MTN started debiting more money than what was agreed,called them and they were like the amount which was deducted all along was not the correct amount, after 1 year and 7 months later.The money they were debiting all along was the amount which was on the promotion.No one has answers now and they still havent solved my query busy escalating it.MTN service is a mess.They even had the guts to debit without calling me and explaining their mess,I had to call them!