Rip-off and horrible service

I bought a 5hr ******** check service from Postnet Ferndale village instead of the 24hr service since well i needed my results urgently. 5hr service costs R150 more than the 24hr service. It took them 6days to give me my results. And to be fair, i just asked for the difference (extra R150) i paid since they couldn't give me my 5hr service that i paid for. Its more than a week now and they still dont want to give me my money. It really pains me to be subjected to such a rip-off. It's my hard earned money, I'm not askin for a handout, i just need my money back, thats all. This is frustrating