Everything is gone after upgrade to Outlook.com

To whom it may concern,

I just signed in today (November 1, 2013) to my hotmail account, via the web (no fancy devices, no complicated applications), and found out there was an upgrade or switch to Outlook.com. Along with the change my whole account is gone; in other words, now I have a new-empty account. How can I recover, at least, some of my email history (= an Hotmail user since you started in the 90’s and this had never happened before)? Probably, the first thing you will tell me it will be about the account not being active for a while; but, if that is the case, why, then,  it did not happen the same with another hotmail account I have (I have a personal and a professional one), which I do not see often enough. What puzzles me is that I accessed both of them today, the one with the successful switch (nothing happened to that one) and this one with the total erasure of my stuff. Any ideas, suggestions, help??

Thanks in advance for any help/reply to this matter.

Sincerely,

AGR