Dairy Queen Grill & Chill

A year ago I had someone from DQ come in and sell me a customer appreciation coupon book. I used it a few times throughout the year. Last week I checked the expiration and it said the coupons would expire on 9/30/2011, on Tuesday 9/27/2011 I went in to this store which I have gone to before and proceded to place my order, when I showed the cashier my coupon she told me that they are no longer accepting them. I told her that it doesn't expire till the 30th which is friday, and she preceded to argue with me that her boss had told her they were no longer accepting them. This made me upset and I left. The other times I had been in there to get food, it has been a pleasant experience, this time not so much and I don't think I will ever go back. How do you sell a customer appreciation packet and then not honor the coupon till the date. She wasn't willing to ask anyone else or honor it and this is not acceptable. They would have had me there eating and getting stuff i did not need for the next 3 days and now they have made a good customer mad and I will be sharing with all my friends to not use this location cause they don't honor their customers.