You seem to have missed a detail in their replies "We confirm that your app has options to report and block abusive users but your app does not contain functionality to report objectionable content." You complain that they haven't answered the specifics of your emails yet you've actually failed to address theirs. Unpopular opinion but it seems like their response was reasonable tbf.
I agree, the author is conflating the ability to report and block a user due to their content and the ability to report specific content of that user. All they had to do is add a link to report the specific contentId that user created. The author was blinded by frustration and didn’t read.
If Google is "too big" to run a competent support department then it should be broken up.