Protocol for When Things Go Bad

Paid for an item here, and waited 4 weeks. Emailed the seller and he said he had a personal emergency and didn't get it out...he apologized and offered a refund. I accepted the refund. That was 5 weeks ago. I have emailed him a few times, w/ no response and have not recived the refund. Silence. What bothered me is that he aparantly had the time to relist the item and sell it again, during the time period that he was supposed to refund me (so his "personal emergency" only selectively prevented him from doing telescope business). I send him a final email, and am thinking the next step is to zing him with a zero. Any expereinces like this?