Does flashing or debranding solve this problem and reset code to 0000 or can i find the code browsing through its file system by a2 uploader
No. Flashing WILL NOT reset the code and you wont find it in the FS either. Considering this is a security feature It would be a bit silly if you could reset it like this don't you think???
And there are no free ways to reset the phone lock code for A2 phones.