Mtn steeling my money

I have an mtn contract almost 10 years i made my payment last month the same as every month now they suspend my account for no payment although i have been paying it from the same bank on the same way with the same ref number from the beginning of the contract. So i phone them just to hear that all of an sudden it not showing on there side. So now i must send them my bank statement to show that it payed even more then the installment. After an week same switch of again so i phone them again only to hear that i now have to change my ref on my bank of me to there ref number and dew to that they can't reconnect the number because they do not see that its payed on my statement. Although i have been paying it for 10 years on the same way from the same bank. But he could see the previous month of april is that has been payed the same way as this month So no phone although its payed I have 2 contract with mtn the last 10 years and is dew for upgrade aug 2020 witch i won't be doing. Mtn must just ask me for money there's no need to steel my money