ipad air locked

help

I have just got an ipad air 64gig but I cant do anything with it.
I choose the language then country then a wifi network but it then says its locked to an icloud account which I don't know, (no its not stolen but a customer return from a large department store)

been reading a fair bit on the web and it seems I am stuffed so guys what are my options please ??

thanks
tim