I used Steinberg Australia support a year or so back (maybe late 2020). I contacted them a couple of times and they got back to me (after a couple of weeks) and resolved my issues in both cases.
I would say if you wanted to make a complaint or make some more noise you could go through the Yamaha Australia Contact Us option from here (from Product Support link):
https://au.yamaha.com/en/support/contacts/index.html