Credit card companies have a mechanism for dealing with disputed charges for exactly this reason. Seller gives Buyer something other than advertised and agree to and thinks they are off the hook because of the credit card payment.
Guess what! They aren't and it costs them money to have a charge disputed.
Contact Taylors and inform them that you are disputing their credit card charge for Breach of Contract, specifically Seller's failure to deliver the agreed to item in the manner agreed to. Further, if you expended any monies to have your local FFL process the transaction, inform them that you are due those monies too.
They won't be happy; they might yell or they might bluster. But their changing of their advertisement is proof that they realize they made a mistake. They are caught dead to rights and have proved that they know they are in Breach by their own actions.
This is a simple contract law issue.
- Seller offered a specific item for sale, listing it's particulars.
- Seller is by definition an 'expert' on the item he is selling.
- Buyer relied upon Seller's description to make decision to purchase.
- Buyer accepted offer and gave consideration ($$).
- Legally binding contract now exists in the eyes of all 50 states and the US Gov (as this included interstate commerce).
- The Seller is in breach of contract for failing to live up to the contract.
I have over 41 years of US contract law experience and you should contact your credit card company
now (don't wait till tomorrow) disputing the charges for 'failure to deliver as advertised'.
If Taylor's raises as stink, I'd consider contacting BATF to inform them of the dispute, the actions you've taken, and Taylor's failure to deal with their mistake. BAFT doesn't have a sense of humor when it comes to firearms issues.