replacing an earbud

I lost a Powerbeat Pro earbud. (BTW, It appears that Apple doesnt support these with the "Find My..." function as they do with their Aipods).

More importantly, Apple was kind enough to help, by phone call, and has promptly shipped me a replacement. They did not have to build a custom earbud or engraved one. While awaiting two days shipping for it's receipt, I found the lost one, amazingly, on the hiking trail on which I lost it. When I called Apple to see how I could return it for credit, happy to pay the postage rather than the $106 replacement fee, I was told that I simply could NOT return it and be credited.

What is up with that? What kind of customer relations is that for a multi-billion dollar company, from whom I have been buying computers since 1981 (and countless laptops and cellphones)??