If I get an incorrect or defective item, I'll only return it if I'm compensated for my time and return shipping. I do the same as a seller.
This has happened to me a couple of times recently. One item was sold as new, but was defective and one item was incorrect.
The seller of the defective part hinted that I should send it back with no compensation for my time or postal costs. I suggested that a simple check before shipping would have caught the problem and I got a refund instantly.
The seller who shipped the wrong part sent me the correct one w/o question.
Both items were freewheels and under $15.