Write it yourself. That is the only way to verifiably get 100% human written articles. Before AI, articles would be riddled with errors, incorrect facts, links that aren't great sources, etc... With ai, I get less errors, incorrect facts, but more broken links. I wrote scripts that fix these links so now AI far beats humans. Like, not even close.
AI has only gotten better from my experience and even though I prefer to read human written articles, AI has gotten me more conversions for way cheaper so...
If the content is "unacceptable" then don't accept it... But at the same time, explain specifically why it's unacceptable. A good writer will fix the unacceptable parts. Throwing it in a "AI content detector" is just pure laziness on your part and super hypocritical.