What is the point of booking.com?

I recently booked a guest house for booking.com, as I had done numerous times previously. I didn't give it much thought, especially because I knew the area. The site map is always useful in this instance, and I like what I thought was protection for the stay, especially in cities with some dubious owners. As usual there was a modest discount, but this was also available on-site. While I won't go into all the details of the guest house, suffice to say I was threatened by the owner and staff, left in an unsafe room both in terms of security and health and safety, and it was unhealthy with bugs crawling and biting me all night. Having tried to reason with the owner who hailed abuse at me, I reverted to booking.com, expecting them to resolve the matter (especially because the property wasn't as described either). After some back and forth, they claimed that they can't help because the property has to agree to any refund or compensation (what kind of system is that!) offering me a small amount of 'travel credits' for their site, which was condescending and degrading to say the least. Booking.com is now making me go round in circles. With an operating profit of almost $10 billion dollars on a model where they win-win, you would think customer service would come first and foremost. Apparently not, you can book a property that isn't as described, be threatened by the owner, and be left with bug bites, and they "can't do anything."