All it takes is a little communication from these folks and all would be right. Is it that difficult to let someone know that some things have come up, and your build has been delayed? I think we all realize that these are folks making some cash on a sideline biz, and we'd be perfectly fine with delays due to life if they'd just keep us informed...and not find every possible way to avoid talking to their customers.
You've got a lot of money hanging in the balance on somebody who is dodging your calls and their financial responsibilities to you. I think a call to Paypal is warranted.
Sadly, this thread sounds so familiar.
Mike.