I can't say that I agree with threatening to pull the roller at this point. If you see that there's been no change in status then that's a last resort, but pulling it when it's not complete is going to get you into a huge argument about "value" that could well land you in court, and it will be their local court not yours. How do you establish how much of the remaining 50% is due? Yes, you can demand your money back, but then they can say that they've spent that money on your behalf, in accordance with contract, blah, blah, blah. Sure, they're in violation of the contract, and they've missed their delivery date but unless you can show intent to defraud you're on thin ice legally, having paid 50% down and them saying "It's nearly done...." I'd go visit, and having a trailer hooked to the truck might send a good message, but I'd be on a fact finding mission to make things clear, not "demanding" at this point. Just my $0.02, and others may disagree.