Booking.com Customer Service Failure

I have been a loyal booking.com customer since I started traveling in my early 20s. However, chances of me moving over to another booking platform is highly likely after my last experience. I often book rooms with no prepayment and free cancellation due to the fact that plans change. This time, the hotel took 50% off my card when they honestly weren't supposed to. I understand a small holding fee to check the card but if I had wanted to part with hundreds of dollars upfront I would've just paid for the entire booking outright. Anyway, the hotel refuses to reverse the charge or engage with me any further and booking.com has not responded to my customer service requests. In short, it's the last straw with regards to booking.com. If you want good support and customer service, DO NOT use booking.com