Hi everyone I play Worms Armageddon for some time.
But I don't understand why some players are ranked and I still have the same rank, however I had won many matches... why?

P.S.
I also unlocked the Fairly Competent grade, but I still have the same rank.

Rankings have been taken out of the game because of cheaters several years ago. The reason a few players seem to have a rank is because there's some sort of a cheat program that lets you edit it yourself.
Some people seem to think they had to cheat-edit their rank to show newbies who's boss (whereas the game doesn't inform newbies about anything. Even the help bot still says you can be promoted by playing ranked matches).

Ok, got it. Is CyberShadow gonna to fix it?

They were planning to reintegrate rankings, but this has been put on the back burner for ages, AFAIK.

It is currently introduced in Wheat Snooper (http://lookias.worms2d.info/download.php) - the secure logins with real league (www.tus-wa.com) ranks.

And normalnonoobs.com ranks, too. ;)