iCloud account has been locked

The pop up window just popped up when I turn on my MacBook Air and tell me my iCloud account has been locked by security issue, I called the Apple Support and they said there should be 2 problems, 1) the account has been reset for too long. 2) Wrong password login. But 1) I just reseted the account 1 month ago. 2) I didn't even have a chance to login before the account is locked. This problem had came out 1 month ago, and i couldn't even reset by the iForgot , I answered the security questions, but the error message pop up, it doesn't say the answers are wrong, but just can't reset it. I want to raise out the apple iCloud system has anything wrong or not, but the Apple support staff said it's running as usual, it's really annoying, can't access my iCloud email and need to wait for 24hrs to reset by email, what if I run the business by this email account? Please advise this, thanks.

Joel