Last year (pre-covid!) I attended a conference and accidentally took a coat check tag home with me. The coat tags are plastic and designed to be long lasting and reused.
I wrote the conference centre asking if I should return the tag but this was likely overlooked as it’s a major centre and I emailed a generic [email protected] email address and they never responded.
1) Was I mechuyav to write them in the first place
2) Do I need to chase them up further on returning the coat check tag?
You don’t have to do any more than you already did. It is questionable if you had to contact them at all, because in all probability the owners are gentiles. On the other hand, it could be that in retrospect, don’t care about it since it is not very valuable, and they know that such mistakes happen.
Kesiva vchasima tova