What to do about my past out of state income when filing unemployment?

To file unemployment, they ask you “Did you work in a state other than California during the last 18 months?” My answer is “Yes” – which takes me to “The answers you provided to the questions on the previous page indicate that special handling is required to file your unemployment insurance claim.” They ask me to call a number, but the number is busy 19/20 times. The one time I got through to a menu, I eventually got to the area I needed, but it said the operators were busy and hung up. Any clue what I should do?