Don't worry; this will be resolved! :)
Sounds like there was some bad timing with the server going down. Normally, it works like this: You make your donation, you log out, then log back in and you have your coins. Sometimes issues arise and this isn't the case.
Please allow 24 hours for the donation to be processed. After 24 hours, you can make a post in the "Donation Issues" section of the forums if you still haven't received your coins. Look at the rules on the top of the section to see which information you will need to post.