Overcharged on cellphone instalment

<p>I took out a contract with MRP mobile. The set amount was R259.00. 1st month i was charged R420.00 & they said i had gone over my calling limit & data usage so i asked for it to be stopped at R1.</p> <p>This month i went over my calling limit by R26.00 and so i could not use my data unless i recharge. Fine but now my instalment is R738.00 how??? I havent recharged the R26.00 but i still 468MB of data so where is the amount coming from. This is pure *****....from signing a contract of R259 to pay close to R800???????????</p>