Man......there's opportunity for some BAD karma on this thread!
I used to call all the consumer hotlines on the sides of soda cans, Doritos and such. I called Coca-Cola and told them that I received a 6-pack of Coke that had all the pop-tops nearly broken, so when I tried to open each one, the pop-top came off in my hand and I couldn't open the soda. They sent me two coupons, each for a free 24-pack. 48 free cans of soda. Sometimes you don't even have to complain, just call them up and tell them how much you like their product, and they'll send you some goodies.