You have 45 days to the minute to start your claim. After that....
Go to the credit card you really used to pay (Paypal is just the mediator) and phone the 1-800 customer service number. Ask about a chargeback. Cards have longer deadlines than PP/eBay. The clerk will need dates, transaction number and values, so have them handy for her to process the refund.
Here's today's lesson. Never allow a seller to send you a replacement. It is less likely to arrive than the original shipment, which probably was never shipped either.