Seller did not ship my goods after 11 DAYS! Can I request a complete refund from paypal?

I ordered a set of fairy tail keys (18 pcs) set from sammydress.com, The details says ship in 24 hours, but after 11 days the item is still not shipped! I'm pissed off and is canceling the order, but I have a gut feeling that they're going to pretend they don't see the message about the refund and just ship the item, What should i do?I don't want the item anymore! But I'm so scared they ignore the message and ship my items(Their customer service is bad, and takes a day to replies to tickets) and I would not get my refund,Please I need your help on solutions to get a successful refund back!Thanks!