I would recommend having a look at your browser history on the device where you accessed this fake info ASAP! Most browsers can store 2-4 weeks of browser history, perhaps even more and some even allow you to search your browser history for pages you visit allowing you to find the proverbial needle in the hay stack:

Once you found the offending Google search, you'll want to forward the keywords you search, where you searched from and phone number you dialled. Chances are they'll be able to pull up that information from the suspended ad database they likely maintain.
Safe Travels,
James
Hopefully not a dumb question to ask but should the OP take steps to secure their reservation and account? Presumably to do the rebooking she shared the confirmation number which as we can gives you keys to manage the whole reservation (including cancel/change flight/passenger) and possibly even their MilagePlus account if that was revealed in the res or with the agent. Would UA be able to reissue the ticket under a new booking number?
Safe Travels,
James