I am getting doubt as all titled players has premium membership so I thought if ever I will be a titled player can I get free premium membership?

That's right, they all do. FIDE CM's (FIDE rating >2200) as well as National Masters (maybe for any country) get free diamond membership for life as well.

NM, CM, WFM, FM, WIM, IM, WGM, GM.  Is there a WCM?

I feel sad and pity for those players who are untitled as they also play well but they do not get

There is a WCM, but I don't think they get free premium membership. WFM I'm not sure about.

Why chess.com do like that or please tell me or join with me to make all the untitled above 2000 players get premium membership atleast the platinum or gold please....

Yeah, there are some strong players out there, maybe even stronger than I am, who don't get free membership because they don't have a title. But what you're suggesting gives way too much incentive for users to cheat.

Isn't there a list of titled players registered on Chess.com?

As for why, they do it as a courtesy I believe.  Titles are easy to confirm; it's probably a lot more troublesome to verify someone who has a 2000+ rating, and it wouldn't count if that 2000 was on Chess.com.  *shrug*

But chess.com is very secured according to me and later years it can get more secured right! so now what dou say Sir, Please suggest me so that excellent players but unfortunately whose only disadvantage is wealth can get better and who knows those players only can be GM or World Champion later so now if chess.com helps even it will also be popularized. Please show pity for those players and please contribute this my request!!!!!!!!!!!!!!!!!!!!!!! Please encourage!

You have yet to even finish a game.  Request after, not before.

I have an Idea let chess.com take their addresss and let then they give them premium membership and only if they are active members or has more points or has more comments or trophies like this chess.com can check right!

Wanmokewan Sir, I am not talking or I do not want any membership I am just feeling pity about those players please understand and thanks for commenting.

But we can help know by spreading this idea. so please....

Where can I apply for this Diamond Membership?

What a first post Groetzi, lmao.  

i am a CM but i dont know how to add the title in front of my name

http://www.chess.com/members/submit_title_proof

While the documentation does not say it, they do give free membership to WCMs as well.  They ask for proof of your identity and FIDE rating.

I agree with those who say that giving free membership for chess.com rating would create an unworkably huge incentive to cheat.

So how does one get that free diamond/premium subscription? I am a NM.