This is a WAMU autodialer. A lot of companies are using these now. It dials your number, and puts you through to a customer service person if you answer. I called the number back, and it identified the number as Washington Mutual, then requested me to enter the last 4 of my CC number. I hung up.
I have received calls from this number everyday since 9/21 and also several days in July; sometimes they call three or four times in the same day. They never leave a message. I tried calling the number back and get a recording that says, "The Verizon Wireless number you have called has either been changed or disconnected." I don't know who these people are, but they are relentless. I have also received calls from 925-738-0263, 0267, 0252, 0256, 0254, 0262, 0250, 0264, 0249, 0268, 0253, 0260, 0261, 0324 (in July), 0251 (July), 0269 (July), 0323 (July).
OK - I just received another call, 925-738-0250. This was a company calling for Washington Mutual Credit Card Services to ask me for a payment. However, this man had a strong India accent, so this must be an outsourcing company of some kind.