Man did I see that coming... . if it's not obvious, he wants cash because he knows you can contest this bill in court later and beat him legally. If you take him to court and win, it'll take forever to get anything back in cash. At this point, I would try anything and everything to avoid giving him any cash. Refusing a certified/cashiers check is a bad sign... and probably a mistake on his part. Was anyone with you when you offered the check???
There's a good chance that this shop has history. Call the local COC, BBB, and the District Attorney. Don't complain yet... ASK QUESTIONS INSTEAD... Briefly tell your side then let them ask you questions. The more questions they ask, the more they already know. Remember that.
You need to contact a lawyer NOW. Whether you pay the bill or not... CALL A LAWYER... preferably one in or near that local area. If you can pay this bill, you can afford a $200 retainer. Pay it and they'll take you seriously. They might start researching his history and most importantly they'll either tell you REAL legal options or refer you to someone who can. Once you have a legitimate legal representitive contacting him, he'll start thinking about how he's doing business with you.
Hire the lawyer BEFORE you pay the bill, ESPECIALLY if you decide to pay cash... they will help you ensure that you have a proper record of the transaction, including evidence of consent or lack of consent, and some evidence that you are in fact questioning the total amount BEFORE paying. Once you pay, it might be arguable "legally" that you consented by paying. You want to have evidence that he is using possesion of the truck as leverage, even though you offered a legitamate method of payment already. That's powerful information that I guarantee will interest the DA's office... legal or not. A lawyer might even suggest that you "file" something with the DA.
Please call a lawyer... you might be surprised as some of the things they'll suggest you do that you wouldn't think of by yourself. They'll definately give you better advice than I or any other stranger could.
At this point I'd be careful what you mention here (forums) until you get the whole thing resolved... another good reason to call a lawyer. Everything you've shared so far seemed very reasonable to me. If you get to a point where you want "professional" advice from the forum, I'd solicite PM's, CALL them back, and don't forget... that shop probably has FRIENDS in this forum too. Don't get fooled into doing or saying something that hurts your case and don't assume anyone is on your side of the argument... you really need a lawyer.
http://www.nvbar.org/lris/lris.htm
http://www.nvbar.org/feedispute.htm
http://www.lvchamber.com/
can't find them listed
http://www.vegasbbb.org/
(Satisfactory w/3 complaints in 36mnths:
1 unresolved + 2 closed administratively
someone might be in court already... )
AND... only two of the eight shops listed have any complaints at all.
I searched "diesel"
http://www.jsdieselservice.com/
url listed with Vegas BBB, but it doesn't work???
Wonder what this is about:
http://courtgate.coca.co.clark.nv.us:8490/DistrictCourt/asp/Summary.asp
or what this was about:
http://courtgate.coca.co.clark.nv.us:8490/DistrictCourt/asp/Summary.asp
or these:
http://courtgate.coca.co.clark.nv.us:8490/DistrictCourt/asp/Summary.asp
http://courtgate.coca.co.clark.nv.us:8490/DistrictCourt/asp/Summary.asp
http://courtgate.coca.co.clark.nv.us:8490/DistrictCourt/asp/Summary.asp
http://courtgate.coca.co.clark.nv.us:8490/DistrictCourt/asp/CaseNoEdit.asp?CaseNo=91A295817
http://courtgate.coca.co.clark.nv.us:8490/DistrictCourt/asp/CaseNoEdit.asp?CaseNo=90A285136
They've sued and bee sued quite a few times.
These are from ONE quick search (corp. search, "diesel") here... .
http://courtgate.coca.co.clark.nv.us:8490/DistrictCourt/asp/SearchKeywordOptions.asp
Wonder what we could find in an hour vs fifteen minutes...