He cannot refuse to refund your money. You said 2 things. 1. you bought it in a store and 2. it was his personal machine. When you take it back, take the fabric you tried to sew that kept getting caught and have him demonstrate to you how it should work properly. $600 is way too much money for him to tell you he won't refund you. Unless it's too inconvenient for you to go to the store, I would not call him first. But even if you call him he should (as a reputable store owner) be happy to demonstrate on your fabric to show you what might have been the problem. It is actually illegal for him to expect you to *eat* your money like his machine ate your fabric. Good luck. Be insistent! Be stubborn! Don't take no for answer. Take an aggressive friend with you who can help you stand firm that you want a refund. I got my Viking machine for $399. It's not a computerized machine, but I prefer the mechanical machines anyway.