To sum up the story, here is a copy of the email I just sent Nintendo:
Good afternoon
I have been a loyal fan of Nintendo since I received a NES many years ago. My loyalty survived the days of poor PAL conversions, over priced games, late releases and a general disregard for European gamers. Despite all this, my loyalty for Nintendo as an innovational and original company remained strong.
However, today this ends. Whilst browsing the Stars Catalogue, for the first time I found an item that I wished to purchase. Only to find I do not have enough stars, as yesterday, over half of them were wiped away (expired). Despite the numerous emails I receive telling me of new Nintendo products, I was not once notified about the imminent expiration of the majority of my points. All those lonely nights, scratching away at panels and inputting overly complex codes has gone to waste!
I know there's no point in writing this, and I know it's not your fault, but it provided an alternative to making a loud noise in the office and looking very strange.
Thank you for your time