MTN consultants are useless,

So i upgrade my phone and they gave me instruction on how to set up Usage limit of which i did in June , Now in September they debit my account R 1900 claiming that no usage was set, when i call them they say it was set but they cannot revise the amount (What kind of **** is this ?) I have been calling MTN for 2 months now trying to sort it out and i was assured the amount that occurred after Setting my limit will be credited , Today they are changing their Story....<br> <br> How does a Big brand like MTN do such ? Disgusting