Disgusting service from mnt!

I am shocked at the horrible service , I have received from mtn , I was debited R4141.01 from my account and it was only suppose to be R350 per month , I informed my consultant that helped me with my contract , I have a capped account this was a mistake on mtn’s part not mine! I told that I have to contact fnb to do a reversal , which would cost me more money to do and I have to wait just as long to try and fix a mistake that mtn refuses to make the correct effort to deposit the amount back into my account with immediate effect. I have been so patient with you guys , but this service is appalling and the fact that I have to do all the work to try and fix your mistake! Worst cell service company! Please dont use them!