Mtn is the worst

So I've taken contacts with mtn and have been querying the billing issues constantly as they kept on billing me incorrect.

This morning they have debated a extra R1000 and they are advising me to send them copies of the contracts which doesn't make sense if they are the people who had me signed up.

All i have been advised is that they cannot assist me and if they find that the billing is incorrect they will credit me not thinking that people have to live during the month and how convenient of them to say that on a new years day.