Thanks for the replies! Confirms what I thought. Glad I didn't waste anymore money on this. When I say "My Blockchain", I meant my Blockchain account.
So, the non-spendable amount, there is absolutely no way to obtain this? Not even the amount that I invested.
Yes, since bitcoin is non-reversible you can't get it back unless that scammer gives it back to you which is unlikely to happen.
Abandon your blockchain account, don't use it again. Changing password is useless since he gets the 12-word recovery phrase of that wallet for sure. And that, he can access your wallet anywhere he like even you change the email and the password of that account.