Petrol attendet stole my R50.

I passed by Engen 14th Avenue Convenience Centre to top up my petrol tank on 24 September 2019 around 3am. The petrol attendant came to my window and I gave her R300 asking for a R300 top up. She went to pour the petrol and left. I started the car ready to leave, I happened to look at the petrol dispenser and noticed that the amount displayed was R250. I hooted and the lady came out with a receipt claiming that I gave her R250. When I asked on why would she take the money and keep quiet if I'm requesting for more petrol than the money I gave her. She claimed that she told me when she got to the dispenser. However, she didn't. I had counted the money before I gave it to her. I went inside the station and asked to speak to the manager, I was told he was not on duty. I came back a couple of days with no success finding the manager until the 30th September 2019. I informed the manager about my problem, he took my phone numbers and advised that he will review the cameras and get back to me. To date I have not heard anything from anyone.