Out of network ambulance service billing advice

Two years ago, while 20 weeks pregnant during a high-risk pregnancy, I passed out while attending a function in California. I was unconscious for about a minute, and 911 was called immediately. Obviously, in an emergency like that, no one is asking which ambulance service is in-network — nor was I conscious to do so myself.

I was transported to a hospital, evaluated, and thankfully everything turned out okay. A few weeks later, I received a $3,500 bill from the ambulance company, claiming it was out-of-network. I appealed with my insurance, and after nearly a year of back-and-forth, they finally paid $800 — leaving me on the hook for the remaining $2,700.

Now the ambulance service is still pursuing the balance. For what was literally a short, uneventful 3-minute ride (no advanced care rendered), I’m being chased for thousands. It feels completely predatory that someone can be held financially responsible for services they didn’t — and literally couldn’t — choose.

I’ve read about protections against surprise medical billing, but it seems ambulances are often excluded from those laws. I’m wondering:
• Is there any legal recourse or appeal process I can pursue further?
• Has anyone successfully fought or reduced a similar out-of-network EMS bill?
• Could this be considered balance billing or even unfair debt collection?

Any advice or insight would be appreciated. This whole situation feels like a scam, and I want to understand my options before I give up and pay for a service I didn’t even consent to in the first place. Thanks in advance.