they say i owen them

i have contract with clientele mobile about five years then say i own them R150,00<br> i went to the bank to get the statement i just fount that they were taking two different amounds of money where they should take R75,00 then there was R85,00 that i don't know about i send them a copy of my bank statement.<br> They did not reply from that statement it where from last year 2014.<br> They send me the messages that i have to pay that R150,00 or they going to can sell my starter pack with them this staterpack are mine not thers i told them i want to can sell the contract with them i still waiting for them to respond to my letter to them pleas sir will you help me