To be fair to fordham sports these pads are now technically used and they have every right to not provide a full refund.
If you had tried them on in your house and not liked them, had proof of purchase and the original packaging then there would be no issue. The fact is you have worn then in a net and do not have the original packaging.
If this had been a forum sponsor retailer then there would have been no suggestion about someone else providing packaging, let alone someone offering. It's not fair to Fordham sports.
I suggest you pop them on eBay and take a few quid loss on the chin.