What is a good thing to comeback with when someone tells you to>>>COWBOY UP<<<?

I fell out of a booth at Subway while eating a footlong tuna on wheat today and I started crying a little. The female istant manager just walked by me lying on the floor and said in a very condescending voice, "Cowboy up little Miss". It was pretty embarring and several other patrons starting snickering. It will be a cold day in Hell before I set foot in that establishment again.