You only have 30 days to gain a full refund from eBay. You have 180 days buyer protection with Paypal, but unless you can sign this up for their ' Free Return On Us' then here, you have to pay for that fully tracked return postage here, for a mattress it won't be cheap.
You have no comeback if this was bought from a Private seller, too late to claim here.
If purchased from a UK registered busienss who is now not upholding their guarantee/ warranty, then it's to Trading Standards and Citizens Advice you need now, if you wish to pursue this further.
