What you are sharing here I find to be a bit confusing. What I can share is this...
You can report an agent to his/her broker, their local association of Realtors and/or the California department of Real Estate. Doing so must be thought out carefully.
This situation certainly sounds fishy and less then ethical...but the other side of that is you cooperated. i'm sure you signed all the documents...and no one was forcing you to do so.
Anytime the same broker represents buyer and seller, I believe you have a compromise of clients' interests. Your best bet is to have your own buyer's agent who is unrelated to the seller.
I certainly can't tell you what to do. From what you've shared, it sounds like you were improperly guided by a money motivated agent.
I don't know where you are in the sales and purchases,but it seems that you are out of escrow already. You can speak with the Broker in the office that your "agent" works, but beyond that you would have to seek legal advice for satisfaction.