Mtn
Have to pay R1700 for a top up account

When i upgraded my phone i asked that my contract be changed to top up 100... the first month my bill came to R 905... my sms and calls totalled R13 and the rest was for data.. i was using it thinking it would cut off once i reached the limit.. and by the tym i recieved my statement i it had already creeped on to the second month, with the bill being R800. I should not have to pay the excess.. i asked for top up cos i dont have extra funds to pay for such large bills