Unexplained for Interest fees

My Jet account was handed over and I was told my account is owning R1460, made payment of R1500 but now when I call to check if the money was recieved my account has an additional of R1400 added on claiming its service fees.

What I don't understand is how did I accumulate so much interest within a week. Can I please get some clarification because now I am be ****** and ****med. I was to told to pay the R1460 to settle my account and that was paid but now is another amount.

Plus their customer care operators are very rude and unpleasant to speak to. I've even requested a statement to see these charges they speaking about, theh failing to do that.