OneDrive addmitting losing gigabites of content

I've been using OneDrive since it was called Windows Live SkyDrive, circa 2010. After years of using it as an archive for past projects (I'm a graphic designer), I've recently discovered that almost every single project I had there (and nowhere else) has disappeared. In reply, OneDrive escalation representative said “There is no possibility for recovering the data. Trust me, if there had been a single percentage of chance, I would have taken it”. This is unheard of; I’ve lost a large portion of my portfolio from 2012 to 2021. Did it happen to anyone else?