Pay twice

I always wash my car at the same place. For years now. I came end of the year, paid for a full car wash, sat in the queue which took forever and hen decided to leave and kept the receipt. Normally as you go in they collect your receipt and you leave with your car washed. You never get it back. It's like a fail safe. Paid at another petrol station where there was no queue and kept the receipt. Today I went back to the place, took my car through the wash and gave them that same receipt and half way through the wash I was told I need to go speak to the manager. I had to go to her and she didn't come to me...she sent someone to collect me like I'm a school<br> Child. Was forced to pay again and said the receipt was only valid for that day. Granted it was end of last year but you could see the petrol stations name and the price of the wash and the price is still exactly the same! There was no room to negotiate no room for explanation, just spoken down to in the front store in front of everyone. So I paid again. Paying twice for the same service and being refused a refund for the previous one is theft in my eyes.