i'm in MO, and the sign conforms to MO CCW signage laws. of course, all they can do is ask you to leave. if you refuse, then they can call a cop to come write you a ticket. 2 tickets and your CCW permit is suspended.
If you are correct in this, then I wouldn't give it a second thought since you are carrying concealed anyway.
I breeze by plenty of signs like that and don't worry about it (although in Texas, as Springmom said, the signage law here is very specific and we frequently get free "passes" to carry in lots of places that aren't posted correctly
The first point is that if you are an experienced CCW carrier, then you won't be made in the first place. So 99.9% of the time, you go in, buy your stuff, and leave without your pistol even once magically jumping from it's holster all by itself and going crazy on your fellow shoppers.
On the off chance that you're made and they ask you to leave, then why on earth would you argue about it and not leave, expecially if it would result in a misdemeanor charge?
When the irritable lady asks you to leave with your nasty 'ol chillen' killen' weapon, just apologize and say that you're sorry but you forgot that you were wearing it because it's so comfortable and all.
Then leave your shopping cart filled to overflowing where it sits and walk out leaving her telling everyone in earshot: "Move along now, I've saved your lives and you don't have to worry about a thing" while she begins the lengthy job of restocking all the stuff you were
going to buy.
Need answers to your questions?
Just ask.. Carter