This happened several months ago. I'd lost my cell phone and needed to replace it before my parents could find out, because I know they'd never let me live it down. I had to beg a friend to drive me to Verizon because no buses go that far, it was the end of the week and they'd be closing soon. But we managed to get there 30-40 minutes or so before they closed and I put my name on a service list. I was assisted about ten minutes before they closed, and it turned out that replacing a phone wasn't as easy as I'd thought it would be. I was forced to make phone calls, negotiate, etc. etc. Finally they offered to sell me a phone at the full retail price for that day and I could bring it back later for a refund (basically they couldn't give me a phone at the 'upgrade' price without certain information from the account holder). So I finally agreed to do this a few minutes after 6 PM and went to pay.
It was at this point that the woman at the counter who had been walking me through this entire procedure, even AFTER they had officially closed, told me that the registers were now closed and I could not buy anything that day.