Ask HN: My domain registrar (Hover) rug-pulled me for $3000

I registered the domain onlyfans.sexy six years ago as a joke, but this year my registrar, Hover, billed me $3000 for renewal instead of the usual $38. Hover claims they cannot reverse the charge because the .sexy registry (Uniregistry) sets premium pricing and changes it at their discretion. I am seeking advice on whether others have faced similar sudden price hikes and if there is any recourse.