I feel your pain.
And as much as it sucks, I'm kind of glad that it isn't just me having these issues.
Their horrendous help desk is absolutely useless. I spent most of the time trying
to explain to them that I already had a personal licence and just wanted to renew it.
For some reason that was beyond them. They eventually sent me to this forum for help
and that just got me sent back to where I started.
That was the point at which I gave up.
I'm using FreeCAD now.
I wasn't doing anything tricky with F360 that I can't do with FreeCAD.
Just remember to export all your models from F360 so you can import them into
whatever software you end up using.
I used FBX as I can import them into Blender and then export them to other formats if I need to.
To be honest, I wish I could have just stayed using F360 but it's just not worth it.
And even if they sorted out this mess (which they won't) I probably still wouldn't use their software any more.
Because in 12 months time I would have to go through it all over again.