Windows 10: How to recover an account to get a recovery key for a bit locker problem

My wife has just set up her new computer with a brand new Microsoft account. She went to turn on her computer but got a bitlocker problem. She has tried to log into her account to get her recovery key but looks like someone has tried to access her account before and her account is now locked. The frustration has been filling out the forms to recover her account. She has filled it in with as much information as possible but it keeps being rejected. The thing is its a new account and so she hasnt sent any new emails to anyone. How can we recover her account to get her recovery key? We are

:)