Business ProfileforGold Rush

Friday July 5 2024 I walked in to Gold Rush Westminster location. I was selling some gold coins. They quoted me the price of $22,200. I left and came back an hour later to sell the coins. She double checked the coins and confirmed $22,200. I filled out the paperwork while she did her do diligence, including a call for additional approval for the price she quoted me at. It was approved and the wire transfer was initiated. I have copies depicting a wire transfer of $20,000 as we received $2,200 cash on the spot. An hour or so later I get a call from ************************* with Gold Rush. He said there was a mistake and the total number was much lower. The new total was $16,320. **** said we either had to cancel the transfer and get our coins back or take the lower payment. He said there was some mistake on their end but didn't really go into detail of what the mistake was. When signing the paperwork, she had me doublecheck everything was accurate, I agreed to the original price. They have signs in their business stating all transactions are final but now they are trying to undo an already completed transaction. I offered to split the difference as I know mistakes happen but he seemed unwilling. I told them I don't want the coins back and he offered an extra 2% because I was civil bringing my new total to $16,715 less our cash of $2,200 which would make the new wire transfer $14,515. Then a new wire transfer was initiated for $14,180 which again does not match what they stated. I feel like the rug got pulled out from under me and my only options were to take an amount nearly $6,000 lower or to undo the transaction. Their policy is all sales final, is that false advertising?