I still don't know what happened. I downloaded Electrum from it's official site and i'm sure i pasted the correct address. The most likely situation i can think is a downloaded an infected Electrum app from its official site. I'm not a newbie in computers, actually i'm a software developer with more then 20 years of experience.
That's a very bad experience. I lost all trust on this and will never more buy BTCs, better leave my money on the usual investments :p