Billing Errors

I have a billing issue that has failed to be resolved. My contract is for R219 pm but I was billed R279 pm. I queried this in April and was told I will be credited R180 for being billed an extra R60 for 3 months. My last debit was R99 which is incorrect because 180+99=279 which is still not the correct amount.

I have called 140 numerous times. Had to deal with unfriendly and *********** agents as well as computer systems that are always freezing. Im tired of calling and answering all these questions only for my call to be cut when I am supposedly being transferred to another agent.

PLEASE HELP CELL C!!!