Cannot log in again

I logged in the morning, and when I tried it again in the afternoon. The error message just came out and it said "At least one of your entries does not match our records." I called the reps for help, they said nothing was wrong they could find about my account. I changed my password as they suggested  several times. When I tried to log in with my new passwords everytime, the same wrong message just showed again and again. I can evan recerive the notification emails from Citi. What a crap system! The worse I ever used.