I've just been into Grainger Games (local games retailer with half a dozen shops), and bought Ghost Busters for my 360.
I had a look and saw it on the shelf, and as I couldn't see it in Gamestation, and had some games to trade, went and bought it.

The box on the shelf had a 15 BBFC rating so I took it to the counter, got my game, and went home.
I'd taken the sellophane of the game, but not broke the seal, and noticed that it's an NTSC, ESRB rated, "Made in the USA" game.

I've done some research and it seems that GhostBusters on the 360 isn't out til November. Probably why I couldn't see it in Gamestation.  As t's not region locked, these are imported US Games.
My receipt also says "Console Rental" on it, and not something along the lines of the name of the game.

Surely sticking a BBFC 15 rated sticker 'over' the ESRB rating on the boxes on the shelf, and giving you a blatant imported one is illegal. I think selling imported games not rated by BBFC is illegal anyway.

I'd have just kept it, but as I've had problems in the past trading in imported games, I took it back today. I expected a heated debate, but they were fine and gave me a credit note without any hassle (I traded some games in to get it so they'd only give me a credit note).

Apparently this chain of stores in the North sells lots of imports, so when buying games, check they're actually released over here and have the UK rating on them.