just billed 2500.00

i have complained twice this month already about a account of 2500.00 , 35 gig of data for one month not possible...i have had a contract for two years with mtn and never even paid 250.00 .???<br> <br> nobody calls back nor even send a mail , i have been to mtn alberton city and get told thats the price since im on contact and the best is the usb is not even plugged in???<br> <br> can somebody call me and explain . i have stopped the payment at the bank and also reversed this *******