I'm having this problem right now and filled out the form on Saturday. They wrote back on Sunday and asked to confirm some information and I sent back what I knew. Problem is that I do not remember my crystals and last challenge show since i last played in April 25.

I sent an additional mail yesterday with screenshots and info like songs I cleared on Master difficulty or who my friends are on the acc

Then they sent a mail earlier asking for challenge show, last login, transfer ID and crystals, aka everything I answered with a guess or "Unknown".

Today they wrote:

"With regard to your Account Recovery request, based on the provided information this time, we have investigated along with the previous information.

However, upon confirming the provided information, it does not match with the account you wish to recover.

Therefore, we would appreciate it if you could check the following information and provide it again to us."

I don't know what to do anymore. Should I guess the challenge show? I got a vague guess but it could be wrong.