No value for loyalty

I have supported this garage from their very first day of business which was June 2015. Recently they have implemented a promotion to fill 50L of fuel and receive a free car wash. My car wash had an expiry date of 23/10/2015. I went to the premise 20min prior to the closure of the car wash and was denied the car wash. I was asked to speak to the manager who agreed to give me an extension however was very rude whilst speaking to him as well as he passed a sly comment as I was leaving saying \the things customers do for free things". I don't believe this is a fair comment because I purchase more than R650 of fuel per week from the service station. This is not the attitude that I expected since I was a loyal customer of the business."""