Garretson's broke no laws in selling me the gun. They are not required to, and have no way to check to see if a gun is stolen when they take it in on trade. I've talked to a lot of gun dealers lately and none of them check since the ATF has not set up an easy way for them to run serial numbers. They all figure it is not their problem.
Talk to a lawyer. Garretson's may not have a legal responsibility to check the gun but they could be held liable for the contingent costs associated with your spoiled trip. You could recover your costs and be paid for your trouble.
Just because they broke no laws does not mean they are not liable in a civil court.
They sold you merchandise with a defective title. They purchased the gun without performing due dilligence in determining the legality of the merchandise. They also are a Federally licensed firearms dealer, and if they are selling stolen guns, they could have their license revoked.
When I buy a gun in NC, the gun store calls someone (the FBI?) and reads the make, model, and serial number of the gun, and my name and address. After a couple of minutes, the gun is cleared, I write a check, and I'm out the door.
Here's a choice of solutions: Either buy the gun from somebody you know personally, or pay to have a used gun #'s "run" or just buy NEW!
Any new law is an invitation for the other side to exploit the situation to our detriment. Just my .02.