now im being charged for interest...

ok, so last month they charged me for a modem that i was supposed to get free.<br> Celiwe called me to tell me that it will be sorted. my debit Order is set for a max R400. my account is supposed to be R399. after she called me to tell me that it is sorted and the bill is adjusted telkom took R400 from my account. i thought ok its fine.<br> today i received an account that shows i owe R808 and that 408 of it is in arrears, and to top it off they are charging me interest on the arrears amount. and being in arrears is giving me a bad credit history. <br> get my account sorted out. this is really unacceptable.<br>