Ok, so you recently just renewed or purchased a new account with one of the now defunct filehosts, shit. You just lost your money, right? Wrong. You are entitled to claim your money back, as per paypal terms and conditions.
You purchased for example, a Filesonic 12 month account, with "X" capability. Soon as they change that "X" changes to a "Y" the product no longer becomes what you first purchased, leading to enough reason to open up a claim with PayPal and demand a refund.
When you open up a claim, the filehost have the chance to correct their problem, but as we all know they wont, they are left with little choice but to refund you your money, if they dont, PayPal will review the case, and if PayPal are going to be reviewing literally tens and thousands of disputes something tells me the odds are not stacked in the filehosts favour.