why the only my account from the list was tagged when its ownership was changed already and any blind person can see that from security log
Security log doesn't prove who changed the password. The whole, I bought this account and etc has been used before. Not saying this is what you did, instead trying to show you why account buying can be risking.
A user with common sense can get idea from security log that account ownership is changed
You telling me a scammer can't change their own password and claim the same thing? A user with common sense would also understand that. Let's not forget this is bitcointalk after all.
This is the risk of buying accounts. You might as well take it as a lose unless you can prove you're not said member. Sure it sucks but you can thank those who abused the system by buying accounts and using them for the wrong reasons.