I found this forum searching for other complaints like mine. While we are in the US, we have had similar frustrating experiences with Goodstack since Google (and Microsoft) switched to using them as a validator. To save having to retell the entire story I am linking my post on the google nonprofit community forum (which also seems to get no attention from google:

https://support.google.com/nonprofits/thread/392129054/goodstack-uncommunicative-do-they-even-review?hl=en&sjid=12701715506981624633-NC

There are a number of stories there from people with validation issues. Perhaps a larger unified collection of voices would help get Google's attention?