we are definitely only getting a part of the story here... I deal with this stuff daily, and the way I would describe some deals/customers vs the way they would describe me/the deal? VERY different.
here is me pretending to be the dealer in this case (so making up a few things and assuming some others)...
I have this customer who wants a hard to find truck. I get the numbers down to a point where they are happy and we get a deal, yay!... I get lucky and my other lot has one! sweet! after they give me the run-around for a couple days, it turns out they have it sold already... crap. might not matter now anyways, because the customer keeps calling me getting all crazy about not understanding the bill of sale that he signed and thinking I'm cheating him or something. I tell him i'll find one somewhere else and start doing a locate. there are a few out there, but being a big truck month, there aren't many and we aren't making any money on it, so the managers aren't prioritizing it. every place we call says they'll get back to us, but none ever do!!! arrghh! I'm still hoping we can make it happen, but the customer keeps calling me wondering how it's going... we're doing all we can, but he keeps wanting more info... I can't tell them where the trucks are (a. because you know he'll call them and once they get a call on it, i'll get "sorry, we have someone looking at it", and b. it could just mean i did the work for nothing if he gets it at their store). now he wants a time, but I just don't know! he thinks that isn't a goof enough answer, but I have nothing else I can give him unless I lie....
*edit: neglected to mention the whole "letting out" thing... if they are being douches and telling you that you have to take whatever they can give you... then they suck and you don't have to do it. now, if they in in the process of getting you exactly what you want, at the price you discussed... yeah, you signed a deal that says "all sales final" right above your signature likely. if you back out, they are entitled to either keep whatever part of your deposit they have spent to this point (or whatever should it be a truck they got that they don't want), or to try and get all they can out of you if you didn't give a deposit... if it's the latter, they will try to strong arm you into taking the truck as it's easier to give the customer something they obviously want over suing for damages just to
everyone off.
basically, it sounds like you are a bit of an uninformed customer who is dealing with a new car salesperson who doesn't know how to handle you or a dealertrade.