How to "reset" extension warehouse account to exclude old pc's no more in existence?

I’m experiencing big troubles in migrating a couple of paid extensions purchased from warehouse.
In “my download” page within sketchup editor it claims that they are already installed 3/3.
The problem being… At this time I only have SU2019.3 and 2020.0 installed!
So there must be not more than 2 activations in existece.
I suppose that’s because i purchased all of this extensions back in 2015 so they could be installed on old machines i do not own/use/know anymore…
I found an active copy of only one of the 3 “rogue” plugins in my old desktop pc, but that has SUmake2016 and It can’t connect to wharehouse from inside sketchup to deactivate the plugin on taht machine.

And even if it was only that… I should have 3 activation for this plugin and only 2 activations for the other 2 extensions. So probably there are older installation wich weren’t uninstalled/deactivated properly
This is really confusing and I’m goin’mad.

Is there a way to reset the account or to texclude from wharehouse previous pc and leave this one I use wit SUpro19/20 as the only one active??

EDIT. the possibility to create a fresh account with a new mail and migrate all the plugins purchased from old account, would be even better, if possible in some way. And deleting the old account, of course.