NO Payment Received

after i had received 3 sms's to confirm that payment was received in december 2015, I noticed that one loan actually did not go of (R1755).<br> <br> I then made arrangements for January 2016. the order went off as well as my last payment on my other loan. then I received my sms's to confirm payment was received and shortly thereafter an email to tell my payment was not received.<br> <br> i then logged into my account to find out that apparently I owe them more than R8000!!! which is impossible because I only qualified for R3500 at the time and my loans were paid up in full. then they also lowered my credit score from 618 to570...