Round rock nissan Backoff on a Done and signed deal Round rock Texas

Horrible and dishonest people all over. We went on Saturday 5/5/18 to trade our 2014 pathfinder for a 2018 pathfinder. After many hours of negotiations we reach s deal on Saturday close to 7:00pm, like at 8pm on Saturday 5/5/18 they ask us to come back and finish the deal on Monday 5/7/18 because THEY have mess-up a vin umber in their system and they had to fix it but it was too late to do it on Saturday, to come back Monday and be done in a couple of minutes. For our surprise I called on Monday to remind them to detail the new unit, and put gas on it, to my surprise they told me that they could not make the deal because the number they mess in their system related to our 2014 trade-in. They did a physical valuation of or 2014 and offer us $14,500 on Saturday, now they tell me on Monday that they can only give me $13K for my 2014!!  When they appraise our 2014 they did it with the vehicle present, they did their whole evaluation and came back with the 14,500, as we all understand, is not me telling them how much is my car worth, this is an offer that they do. Today Monday they back-off the deal, but to our surprise they even run our credit, so now I have a hard inquire  on our credit, and no vehicle. We did sigh an agreement on Saturday, the dealer document had all the numbers and it was signed by the manager and me, my wife, and my oldest daughter were witness to our agreement. When you have a deal you have a deal, not only morally, but legally they are obligated to move forward with the signed and agreed deal.