Call BMWNA, Service Manager, General Dealership manager, BBB, and your local congressman or representative. Not to mention post your story on
www.dealerrater.com for everyone to read. If I were you I would have spat in the techs face if he said that to me, or in my case I'd have got 2 inches from his nose and scolded him in an attempt to provoke an attack. Who takes BS from corporate employees anyway???
You do know a push/slap/or any other petty assault is taken like a grain of sand and rarely leads to any significant judicial consequences in big cities where DA's are loaded with cases...