Usually your credit card gives them a month. Then when they don't deliver they pull the payment back and the charge is taken off your card. The seller shines you on for thirty days because of the item becomes available and they ship it before thirty days is up the cc co won't help you out. You do have to start the clock by contacting your cc.
I've heard Chase and Amex are the best cc for consumer protection.

I went through this with rightobear last year.