Foam Mattress Topper for Double Bed (Welling DA7)

Brand new, I tried it once, it is no good for the arthritic pain I ordered it for. I paid £73 for it online, I requested to send back , they refused and were very unhelpful, so I gave up in the end! It's basic foam, 9/10cm thick, has a removable cover. It may be useful for cushions, upholstery etc.