Is Book a Book legit?

On the 21st March I bought a book online from Book a Book and the shipment was supposed to take 4-5 days till today I have not received the book.,I sent them an email on the 8th April and their response was the book has been dispatched and it will arrive on the 12th april and If you call they don't respond, I sent them several emails asking them to cancel my order and refund my money and no response, please help.