How did you pay?
If you use Paypal, they allow 120 from PAYMENT to open an Item Not Recieved dispute.
Their Resolution Centre is at the top of your PP account page under Activities.
Did you pay with a credit card? While each card has its own policy, you can phone the 1-800 number on the card or your monthly invoice about a chargeback. Most cards allow about 180 days from purchase for chargebacks.
If you paid with a debit card, balance, or gift card you cannot get a refund.