I'm constantly amazed at how many companies will make you send something back to get a refund / replacement, even if it only costs a few bucks.
If our customers receive a defective item that costs less than $20, we simply ship them a new item immediately, without asking them to return the old one. It only costs us a few bucks, saves the customer up to 2 weeks of wait time, save us having to process the return and usually earns us a life-long customer and vocal advocate. It's a no-brainer, and I don't understand why more companies don't do it.