Got payment twice for goods!!!

Goodafternoon, I turn to you for help please. I work for a School in boksburg. One of our Men's teachers bought music good to the value of R2368.00 on 28/08/2015 for the school. He paid music mates the amount from his own pocked ( he would claim the money back from the school for the purchase). I (the payment officer) then payed the money again but unfortunately I payed music mate instead of the teacher.!! Now almost a month later after numerous phonecalls and e-mail's they do not want to pay the money back to the school whom desperately needs the money. I've spoken to Justin the storemanager and Roger the accountant. Everytime they just say oh I forgot or Justin says I must speak to Roger whom then says he will do it now !!! Please this was an honest mistake from my side to pay music mates instead of the teacher. Please hello peter can you help me solve this problem<br> <br> Regards Yolande Hattingh <br> ***/***