How do you report an employer for treating you as a 1099 Independent contractor, when they actually treat you as an employee? And can you report this anonymously, or will your employer know who reported them?

???? How can they be treating you as both an IC and an employee?

Anonymous reports seldom get treated as anything of a priority. The regulatory agencies won't go out of their way to tell the employer where the report comes from; that doesn't mean the employer can't figure it out.