I think a note/letter to their supervisor is the best idea.
Something about a good ole' old fashioned letter (not email) that really speaks volumes. It shows the event was important enough for you to take the time and compose a letter.
Ok, duh! I just re-read your post where you said it was a MS CM.
I think it would be:
Disney Vacation Club
ATT: Carli D'Agostino, Member Satisfaction Manager
200 Celebration Place
Celebration, FL 34747
I'm guessing it would still go to Carli but I would send it to the main WDW address too. Also, FWIW, you might want to include your member # with the rest of your contact info.
I would write the above mentioned letter to management, but I would also purchase a thank you card and send it to the CM at the DVC address as well. I love it when my boss gets a compliment about me, but when I actually receive a thank you card it REALLY means alot. I keep them forever in a file and pull them out to re-read on difficult days.
I called MS and a manager suggested that I send a letter to the CMs supervisor. He gave me her name. I also asked if CMs are allowed to accept small gifts and he said "yes." So I think I will include a small gift card with my thank you note. Thanks to all for suggestions.
All good advice, particularly for the situation where it is a MS (not M:S ) CM.
What we do for any CM is carry around some thank-you cards. I can't remember where I saw them, but they are MS Word docs with 8 cards to a page. You can customize them - they have a Disney character and something like "Thank you for making our Disney experience even more magical". We have a few out each trip, and the CMs are uniformly appreciative - one young lady even got a little teary-eyed.
Of course, we also send official letters when warrented, but these are more immediate.