TransUnion Or someone posing as TransUnion Received a letter asking for more info. Internet

I received a letter from "Allstate" where I recently began a new homeowners insurance policy. The letter explained that there were address inconsistencies and I needed to contact "TransUnion" to verify my address. I called the number, which provided an automated system, and before I knew it, I had entered in my zipcode,  SSN, and birthdate. Once the system said "We are unable to process your request at this time" I knew I had been had. (feeling stupid)

When I goggled the phone number, I saw someone else had received the same letter. 

Not sure what to expect, but I will be on the lookout for identity theft. 

Ugh.