Maybe this info can be added to the OP, as well as a direct link to the Club Nintendo homepage: https://club.nintendo.com/home.doWhy are my Coins listed with an expiration date?
Unredeemed Coins will expire two (2) full Club Nintendo years (July 1 - June 30), plus whatever is left in the current Club Nintendo year, after they are earned. Example: Coins earned in March 2009 would not expire until June 30, 2011. Please refer to the Terms and Conditions for more information.