Misleading/incorrect item descriptions

[muhardigre0]

I recently won an item in an auction. 

It was listed as one thing but what arrived was another. 

Both are of the same type but  the size is very different. 

The seller  told me to file a return. 

That was their only option. 

They didn't offer to send the correct item.

I'm really torn as to what to do.

The seller has many other products of the same description listed  and I don't think the seller has the product he describes. 

Even though it was a decent deal on the product,  what should I do