contract i didnt ask for

My cell number was changed to contract,I receive R50 airtime every month. I'm puzzled as I have never visited a branch to sign up for this,I've asked for it to be cancelled no one has assisted me. I asked them why did they sign me up for this and who gave them a go ahead,no one gave me a straight answer!now I need to run around cancelling something I didn't ask for. I'm under debt review this is making my life even harder. Im unable to access any services through my cell fone because of this. Ive had it honestly.Who is going to pay for this? Why do the do this? We all need to reach our targets at work however we do not,do *****,as we have children to feed and bills to pay! I need help I've tried every thing possible,hopefully this will help me.