I'm struggling to believe you have a dozen new vacuum cleaners in your shed. It's quite an extraordinary claim. Are you willing to share some evidence?
Sure. It's cold, rainy, and midnight but here's what came up in my email when searching "vacuum". It's not all, and you can see some I didn't reply to but -
I was looking forward to seeing 12 neatly stacked & boxed vacuum cleaners in a dimly lit corner of your shed ;-)
That said, thanks for sharing the emails/headers.
It's curious that Amazon hasn't flagged you for purchasing & reviewing multiple similar items in such a short span of time. I would imagine it would be quite easy to spot someone who's bought and reviewed 12 vacuum cleaners in a 2 or 3 year window.
https://imgur.com/a/F0u9xVM