Please help

I am trying to log into my subscriber account and it says "Please answer this security question to verify your identity / Enter the One-Time Password sent to your email address". I get the email with the password and I enter it in the required field and nothing happens! Please I am a paying player and this is ridiculous that I cannot get into the game. Could the admins please advise what I should do. I have tried this email password many times with different OTPs and it just does not work. Please remove this security message now.