If there are enough DISPUTES, the sellers account will be suspended. Negative feedback is nothing more than a warning from one eBay community member to another.
You should open a dispute with eBay (you said you did). Depending on your payment method, you may also have a guarantee through PayPal. Open a dispute there as well. The thrust of your complaint should not be that the person did not send you an item, but that (being broken) it was not in the described condition. Photographs of the item help back up such a claim.
It seems like many people get burned over and over again. There are good people and bad people on eBay, just like everywhere else. Before purchasing, I always thoroughly check the feedback of the person I'm doing business with. If they have a "chronic" problem, I won't do business with them.
I also check the feedback of those who left negative feedback if there are only a few. Sometimes, those who left negative feedback are whinners, and scammers trying to blackmail free goods or something from sellers. Check what other sellers have said, and what they've said about others - their opinions may not count based on that.
An excellent tool is http://www.toolhaus.org/ where you can put in an eBay id and see just the "bad stuff".
I don't know what you bought, or how well you checked out the seller, but it sounds like you took a chance on someone with a bad score and they continued to earn it.
I wish you good luck with your disputes.