i recently got banned for posting and sending personal messages to my original account even i didn`t made anything wrong.
i'm confused a little bit, so are you saying that you message your other account? Why would you do even do that? It makes no sense at all

.
what should i do ?
Is there any chance I'll be unlocked ?
The only thing you can do is to appeal or
just forget that account and make a brand new start. If you will push the first one, I am not sure if you will be given a second chance by mods because first, you're guilty (whether it's just an accident or not) and second, you need first to present a strong reason why they will forgive you. I'm not discouraging you but decisions of mods' are final as usual.
You shouldn't really be encouraging him to break the rules of the forum. The user is banned not just that account. Creating a new account and posting outside of an appeal style thread in meta is ban evasion and that is against forum rules.