How I Can Get Serial Key?

Get a refund. EA likely won't provide you with a key just like they haven't for my MOH10. Official server shutting down end of year anyways. Vietnam has 0 players exactly right now and SPECACT you may already have for free + it's worthless skins.
Get a refund on the bundle and buy the base game only for half price.
Community server has free Vietnam and SPECACT

Wow lol, yeah I just saw

Great timing...

I bought Bad company 2 bundle from steam and I already link ea account to steam why my game not show in EA account.
what I've done by myself just redeem vietnam and Specact DLC to EA account cause steam gave me CD-KEY but not for the main game.
What's wrong with it again? 

Hello,

I also just recently purchased it as well and tried  to ask for help in help.ea but live chat/online chat didnt come up so it didnt work.

I can't login to Battlefield: Bad Company 2 on my steam version of the game, despite having purchased it in 2016. 

I have the game in my library from when i purchased it on Christmas day, 2016. This was one of the first games i purchased on steam as that was when i got my PC. The game is not on my steam account via EA play, i paid for it through steam's store page

Did you get any help, im having the same problem and i just bought the bundle sold on steam...

No, not yet. Steam support replied to me almost instantly, but just to verify my account info before they go forward with anything. No substantial response from either steam or EA yet.