Sometimes people have better success if they call the store instead of showing up in person (I don't know which you did, John). The theory is that the store considers you much more willing to not buy from them if you just need to hang up and call someone else, as compared to leaving the store. It sure worked for me at Best Buy, and then I saw it as a story on (I think) 20/20.
Just something to try out if it comes up again for any of you.
BTW, welcome to the forum, John!