FNB refusing to reverse an ******** deduction

i am having a problem with fnb, they are refusing to reverse a debit of close to R4000 by telkom. i have been struggling with telkomto resolve an issue but telkom doesnt care because they know that they can always debit my account without my permission. i have 199 telkom account, which quickly went to R700 and they R3999. i do not have an agreement with telkom for such an amount, i have bills to pay and now my account is in arrears and fnb is offering me loans. i do not want loans, i am asking fnb to reverse the debit by telkom, telkom can produce such an arrangement if they feel that it does exist, i have emails form telkom acknowledging that the account i have with them is for 199, how dis we get to 4000. please reverse my money so that i can fulful my obligations. ive asked fnb to stop and cancel this debit but it keeps coming up. Now i cant pay my rent and the land lord is theatening to kick me out, In a few days, i am likely to be homeless.