I was in a similar situation, I actually wanted a domain for proper use (not like you homeless people squatting on domains ) and after an agreed price the mongrel backed out. This is after dragging the process out for 5 weeks, waiting 5 to 8 days between responses.
I say name and shame, that's the idea of the forums right? To be honest, knowing about these sort of dealings and situations is the EXACT reason I joined and participate in these forums. The more we know about each other, about who is in the industry and who the cowboys are, the cleaner and better it will be.