Petrol attended did not give me change

on the 27 of November I went to get petrol at the Engen garage in Vosloorus and i the petrol attended did give me change even though I forgot it he did not even try to stop me as i drove off and i did not drive off quickly. I then realised that I left the change and i decided to go back to the petrol station (later on and the next day) thinking he left my change at the cashier but he didn't. I then asked about him and apparently he was not in. Is this how Engen Petroleum workers operate, ripping people of their change. I am disappointed