My hotmail account has been blocked. My information in records is very old.

I have a hotmail account for more than 12 years. I just configured for the first time my account in a smartphone, and got blocked. Microsoft is asking me to verify the account, and phones on records are very old (we have moved countries several times). When I go through the verification page, we manage to answer many things around the recent activity, but still there are questions related to the time when we setup the account 12+ years ago and we can't remember, so that answer from Microsoft is they can't verify. I am waiting a very important email, and this is creating a lot of problem and stress. I just submitted an on line case. If I don't get this resolved, I swear Microsoft will lose a customer forever.