Bed Wasnt as described, brought it home paid cash in hand

[rimz-2009]

Brought a double divan through ebay. Picked up around 8pm ish, we didnt have time to loom at the item properly due to being late and the base of bed looked ok. After getting home and putting it up the mattress was so bad that when you sit on it you can feel the springs. I contacted the seller for a refund or take the mattress back as its not even something you would sell. The seller said to take it up with ebay as he wont except returns. The description of the bed was orthopaedic mattress and was only used for 2 weeks. The base was ok but the mattress is not used for 2 weeks or orthopaedic. It cost me £100.
What shall i do as its not fair on me that iv waisted money and drive time to go get it. Im sure there the seller should give me something back as to me buying another one. Im very disappointed. Can anyone help me how to go about this please.
Thanks