In reply to Ian Patterson:
> To be honest if I looked up opening times and don't see a specific mention of Christmas opening I would look further before making a decision
I would too, but what's particularly crap about the Depot site the OP links to is that it has a prominent "What's happening today!" bit that is clearly just scrolling through the usual schedule automatically without taking any variations into account.
I wouldn't assume that the 'Tuesday' opening hours apply to a Tuesday that also happens to be Christmas Eve, but you can't really blame someone for thinking that 'Today' means today.
Perhaps more to the point the appropriate attitude for the member of staff on the desk to adopt with a customer who's a bit exasperated about that is apologetic, not pissy.