Good Afternoon,
I am an old account and I had donated loads of money. I played on neltharion, and I had many level 85s. I'm just hoping for some form of compensation as I plan to play of one of the WOTLK servers now. I had stopped playing for a long while due to personal reasons, but would like to play again. I am not exactly sure if this is the account I had used back then. I had many characters, a few are Zailyn, Xailyn, Zailin, and Zailan. If you would be able to help me, that would be great! Thank you!
Character transfers from Neltharion to Icecrown were available but it's too late now. There were no refunds and the characters were not given anything good so you haven't missed much, other than not having to level characters. You can make a support ticket on website here to find out if there is anything they can do for you.
You will not get any compensation or coins back. If you were absent during the Moltdown/Warmane being born you were eligible to receive some compensation for up to a year or so but that option expired quite some time ago.
TLDR; They don't give compensations or refunds for donations because they (donations) are freely given money. You just get coins as a thank you. You will not get anything back.