I quit Minecraft and gave away my account. This was 5 years ago, now I want to play again but I can't log in. The password has been changed, and it is linked to another Mojang account. I don't have the transaction ID. I do have access to the email it was created with, and the PayPal account I paid for it with. I looked in my bank history, but that transaction is long gone. I can't make a new account because I don't want to pay another $30, plus I wouldn't get back my old username. I know I shouldn't have given it away, but I really thought I was done with Minecraft. Is there any way to get back my old account?
Can I get back my Minecraft account?
You have to make a new one
Nope
Sorry, no.
All you have to do is ask the people who take your Minecraft account.
I'm sorry to report that your account is practically unrecoverable, mostly because it's linked to another person's Mojang account (which effectively claims the old Minecraft account as their own) & functions as "proof of purchase" (since the date of purchase is noted on the account, once linked).
Even with proof of purchase via an e-mail with the purchase details (from Mojang or Minecraft), it effectively boils down to your word against the account holder's word & the burden of proof (for the purchase & that your account was taken by another person) is all on you… Which you don't seem to have. Even with proof, Mojang will likely be unsympathetic as you mentioned that you freely given your account away to another person, who by Mojang's perspective IS theirs.
All you can do is just create a new account & repurchase the game. I know this isn't what you want to hear, but it's the harsh truth that you'll have to live with.
It's gone.