I checked my account today and the coin balance is correct, so the bug must be fixed. If it happened to anyone else, your balance should now be correct.
Also, post-play surveys now appear after only seven days of registration instead of a month, so you can get to them sooner.
By the way, I wasn't able to link my Club Nintendo account to my Wii Shop Channel account. I believe the message said something like the account name doesn't exist. Did anybody else have a problem with it?