So sorry to hear all of this. I just went through this nightmare with VRBO. Luckily for me, I live in a small town and have always been in contact with county tax collector by first name. She is completely aware of the situation.
It took me weeks to get a statement from VRBO admitting that they will take responsibility for any indifference.
They just started collected taxes for NC. They had me in the wrong county. Now…they would not admit if they would forward the taxes to the correct county. I worked with my local county tax collector and copied her on all correspondence.
In NC the law is that the “facilitator” is responsible for all taxes if you contact them within so many days of guest checkout and they have not remitted the taxes to you. So I plan to contact VRBO every single time for a booking and when guest stay ends.
In NC my 13% lodging tax rate is also applied to the service fee. Have you checked into your jurisdiction about that? Are they applying taxes to their service fee?