If you've recently purchased an item and it breaks unreasonably soon under normal use — I'd say less than 90 days, for most things — take it back to the store for a replacement or a refund. I tend not to buy the same junk twice in a row, so typically I'd just like my money back so I can avoid this problem a second time. This is a situation where store associates and managers like to give you a hard time — "How do I know how it broke?" — but don't let them beat you. Stay strong and stage a sit-in to get what you're owed if you have to.