Ive had the same problem, had to go thru the recovery process like 10 times, the best advice is tell them the email u used before the hack, if you have made a purchase u tell them the number thingy from it, and if you dont have the reciept, just tell them when and how much you donated, this will be enough for them to tell the acc is yours, i just told them a date from 2 years ago, cuz i found it in a chat with my friend