WORST SERVICE PROVIDER! I DO NOT RECOMMEND THEM!

I have an iPhone 14 Pro Max on 24 month contract with Telkom and this is the second time they double debit because I am apparently in arrears. I previously called in so that they can change the allowed debit amount but obviously it has not been changed ! Apparently my account has been debited because I am in arrears with R53(I had no idea I was even in arrears because I was under the impression this was fixed). They debited me a week before I got paid and a week before my actual debit order date! My account is not sitting on a minus and I cannot do anything! I want to cancel this contract asap! Telkom is ridiculous!