Like they had the big tripod thing laying across your hood? That's F'd up.
It's hard to not let your emotions get you, especially at 18, but next time play it cool and snap some cell phone pics and give yourself the upper hand. Then you have proof for the popo too if your car is scratched or damaged.
When I worked in cust serv I loved when ppl flew off the handle, I'd argue right back to them and deny them what they wanted or be uncooperative.