Asda gas station

I am a new driver, and a few days ago I filled up my car at a self-service Asda gas station. You know how we have to pay before filling up. I forgot I had already paid and tapped my card before leaving. The next person filled their tank, and the money was debited from my card and it was a lot of money. I contacted my bank about it, and they suggested I speak to Asda. The customer service advised that I talk to the branch manager. I just want to know if it's worth contacting them or if I will get a refund for this.