You have been given great insight into how to best proceed. A word of caution....before reporting anyone it is essential that your information is totally accurate and that you have a means of providing proof to support the alleged activity.
Reporting DRE violations is still a little antiquated (very old school).
Go to the DRE website below
Click on Consumers
click on "File a complaint"
You want to click on the form 519 A
It is a fillable PDF. I complete it, then print it to a PDF so I have a record, print it out, and mail it in to the DRE office.