My communications prof complains all the time and she gets so much free stuff. She got a free round trip flight anywhere in the world, a $1000 to fix her desk, her kitchen counters replaced when the stove installers broke them, and the list goes on.
Once you know how to write a complaint letter, you will get so much stuff. Just make up a story about how you bought a bag of apples and two of them were moldy so you want a refund?