Empty trade-in box received for Apple Watch Series 6

I upgraded my Apple Series 6 watch to an Apple SEries 11 watch last week with a $50 trade-in arranged. They said they would send the packaging for the trade-in.

Well, yesterday I received a "mystery box" in the mail. Upon opening it I found it to be empty except for some padding material.

NO INSTRUCTIONS!

NO RETURN LABEL!

You assistance in completing this evolution would be appreciated.

Thanks!

Buddy Knight

Fort Worth, TX