Four digit password

I am out of the U.S., I switch my regular plan phone to a Pre paid go phone.
I call from my country.
They told me that I have to refill my phone number before the end of the month.
I go to Att go phone page and they ask me for a FOUR DIGIT PASSWORD which they never gave me I am trying to contact ATT By calling them to all the numbers possible but they keep me asking for the password before connect me to a representative.
What can I do, I don.t want to loose my number.