My bus fare change

Good day

On the 2nd of April 2021 at 10:37 I tool a bus from Newtown A to Market and I paid R100 for two passengers.

When I got off from the bus at Market I forgot to ask the driver for my change and so I called Durban Metro Bus and I gave them the bus number 10313 which was printed on my bus tickets. They promised to make a follow up and they called me back saying that they will keep my change of R72 but disappointingly I have not received my money even today. I do not understand why.