My question involves a consumer law issue in the State of: Washington
So I have a pair of headphone that broke, and I sent them in for a replacement. The manufacturer sent back a different model (one tier lower cost) to me. I know that if something is mailed to you without your consent, you may consider it a gift and may legally keep it free of charge.
I notified the company, and they said after I mail back the headphones (the wrong model they sent, they'll pay S&H) I'll get the proper model in about 2-3 weeks.
My question is, am I legally obligated to return the headphones that they sent me in order to get the proper replacement? It seems wrong that due to their error I have to wait another couple weeks.

