Passing the Buck

My balance as of 14 December 2017 was R1441,37 and I was given 20% discount . I then paid R1154,00 on the 15 December 2017 to settle my account . On the 27th December 2017 the debit order of R1300 went through . I have been requesting refund since from January until today ( 15/02/2018) I'm not paid .