Stranded in Faversham & sleeping in the car

My girlfriend and I booked a romantic getaway in a cosy country cabin. On arrival, the owner informed that booking.com had overbooked our cabin, showing proof, and explaining that she had no additional availability. We spent 2hrs in the car park on the phone with an advisor (mostly on hold) who wasnt able to get his supervisor on the phone. He provided a refund (without our agreement) and wanted an additional payment to book a studio flat in Kent as an alternative. As I explained this was not suitable as an alternative paid accommodation, he offered a 1 bedroom flat 60 miles away. We spent an additional 2hrs in the small town on/off the phone with other advisors trying to speak with a supervisor, and get somewhere to stay. The supervisor finally got on the phone at 8pm, being very pedantic and blaming the cabin owner, although our payment was sent to them as the agent. She refused to provide emergency stay without us paying again, even though I explained I didn't have an additional £360 in the bank. Having no additional funds available as the refund takes 14days, we will be sleeping in the car and driving home tomorrow. Tired, destressed and anxious about our safety. Will never use booking.com again.