I have OCed in Radio Shacks in NC (Raleigh, Fayetteville, Washington, Greenville), VA, WV and PA and it has never once been an issue. In fact the staff at the RS in Washington told me they thought it was a great idea, and they wished more law-abiding citizens would OC, and that I was welcome in their store any time. (of course, the fact that I bought over $100 worth of stuff probably didn't hurt...)
Sounds like you have some sort of carpet-bagger manager who transplanted from MD, NY or NJ running that store in Lexington.
As far as I know, RS has no corporate policy prohibiting firearms carried by customers, and uses the "we follow state and local laws" policy, like most big national chains are moving to these days.
I'm especially interested to hear how they handle the part where YOU were asked to leave, but your wife--who was also OCing--was not.
You might actually have an actionable situation there--against the individual who asked you to leave. It is actually against Federal Law to discriminate against someone based on sex. Since they didn't ask your wife to leave, it's obviously NOT about the gun.
Please keep us posted on what you hear from Corporate.
And you might consider "lawyering up", and having a letter sent to that manager letting them know that you are looking into the possibilities of filing an Federal 1983 Civil Rights violation lawsuit against that manager as an individual (which makes that person PERSONALLY liable for any settlement that may come from such a suit...) That usually changes their tune quickly regarding your rights...