Paganism is not a religion , it goes like this
Paganism = the cultural live styles of really smart people
Wicca = the religion of Pagan
Witchcraft = the magical practice's of Pagan people
That's my view .
As for your book store I'd right them a letter stating your disagreement with the treatment of your RELIGION . No need to say anything about legal action and the violating of laws , just don't do that