Post minecraft transition I can't access my old mojang account

That's normal, you can't access the old Mojang account after the migration, you need to use the email you used to migrate the Mojang account to, in the launcher you need to select Minecraft Java and then Microsoft login and then use the email you use during the migration process

That's the issue, it wasn't linked to a Microsoft account at the time, as it was hacked in 2021, before the migration stuff which came about in 2023 or so. Thats why I tried to go via mojang themseleves at first, but as I say they just pass off any and all account issues to Microsoft now. Then when I got the new account, which used my current Microsoft account (the one I'm posting these support messages through), which uses the same email address that the old mojang account used. So it's unfortunately not a case of regaining access to a Microsoft account, I'd need to be able to access the old mojang account which I'm pretty sure I can't do that anymore, that is why I asked about migrating the username over, as I don't believe the old account was ever migrated in the first place and so shouldn't be an active account anymore as you can't play on mojang accounts?

How do minecraft.net and launcher have anything similar? What I said is, I can't get access to the minecraft.net page as it says I haven't bought Minecraft even though I have and my Minecraft launcher has everything ok, except for the part that I can't login into my Mojang account because I think it was deleted

The Minecraft migration from Mojang is on a separate Microsoft account. How can I access my purchase?

I don't think Minecraft for Windows is used on an Xbox, right? I'm using a PC and moved my account to Minecraft for Windows for the whole shutting down Mojang accounts access in a few days. So, on my PC, I can log onto the server through the Mojang account but not on my Minecraft for Windows account. Those two accounts should work when logging into a PC server, right?