Revolving loan shock

Hi, I have a revolving loan with FNB. I paid extra funds in order to access the remaining balance of the account however no funds were available after the transfer. i am now being told that my cheque account affects the loan account and that the funds will not be available. I then asked that they reverse the extra money i paid and its been days and still waiting for the funds to be reverse. I need the money desperately and i am not being assisted