Argos store just sold me a used second hand slow cooker, what compensation should I get? I had to get a return?

bus ticket to get to the Argos store after reserving the item online. The bus cost me �5.90 return, I waited for 45 minutes to get home in the pouring rain. When I got home I took it out of the box and it wasn't wrapped in a bag and the cable was loose so I took a closer inspection and it had food on the rim of the lid. I've phoned them and explained the bus travel but now I have to go back to the store again next week, I hope they compensate me more than just the bus fair. How can they resale used goods like that, perhaps I would have been better off going to a market stall instead of a big brand name like Argos and what worries me is not just the hygiene matters but why was it returned in the first place. It's a James Martin branded 5 litre slow cooker made by Wahl. Perhaps it's not such a good product? That's my whinging over with for today.