Paypal requires not only that you open a case within 45 days of purchase, but that you use Confirmation of Delivery for the return.
If you cannot prove return, you lose the case.
And you have to upload the proof, PP can't do it for you.
So.
Go to the credit card you really paid with. (PP is just a mediator). Call the 1-800 number and ask about a chargeback.
The clerk will need all your information about your transaction dates, amounts, currency, tracking numbers if any.
Some card will accept proof of Shipping instead of proof of Delivery. Some won't.
Cards have longer deadlines, from 60 to 120 days, but call now.