WorldMark by Wyndham – Unresponsive management

We have been able to make this timeshare work for us over the past 20 years, but it has been anything but easy. Wyndham bought Worldmark years ago, and then asked all of us to "upgrade" to TravelShare, ie. spend more money to buy more. We have not, and in many ways are treated like unwanted step children.
About 3 years ago, WM "upgraded" their website, and it is still not working correctly. We have had trouble making reservations for 3 years now, and have been told every year "sorry, we are aware of website issues". We often cannot see availability, sometimes the website shows availability but when you try to book you are denied booking due to "no availability". Reservations is not open when the booking window opens, so if you can't book on the website at popular locations, you are basically out of luck..."sorry" is all you get. No accommodation of this known problem, now the last 3 years.
I wrote it off as "learning curve with new website" initially, and did not use our vacation credits that year due to inability of making a reservation. Now, it is the same 3 years later, that clearly shows either incompetence or complete lack of caring, or both on the part of management.