I've purchased gears 4 .and received the entire xbox 360 gears collection codes.but only two ...

I've had a chat with the support. They've said they woll discuss my concern. But nothing till now.

You would have received the correct codes. As it states in the game's description: For a limited time, purchase and redeem your copy of Gears of War 4 and get the entore Xbox 360 Gears of War collection for use on Xbox One!

So the codes are meant for console use not, Windows use. Gears 4 is the only one that's available in the Windows Store, so there would not be a way to download the 360 collection through Windows.

Hi Jacky. I believe that the deal containing all of the previous GoW games was only a
pre-order bonus. The game launched on October 11th, so if you purchased on the 17th you may not have been eligible.

This is what I found on Xbox Wire:

Finally, all pre-order customers will receive the entire Xbox 360 Gears of War collection for use on Xbox One. This includes all four previous games – Gears of War, Gears of War 2, Gears of War 3 and Gears of War: Judgment –
and is available only as a limited time offer.

Read more at http://news.xbox.com/2016/08/10/gears-of-war-4-pre-order-bonuses-detailed/#04L116ALGxu0PJ5c.99

Hi Jacky. I believe that the deal containing all of the previous GoW games was only a
pre-order bonus. The game launched on October 11th, so if you purchased on the 17th you may not have been eligible.

This is what I found on Xbox Wire:

Finally, all pre-order customers will receive the entire Xbox 360 Gears of War collection for use on Xbox One. This includes all four previous games – Gears of War, Gears of War 2, Gears of War 3 and Gears of War: Judgment – and
is available only as a limited time offer.

Read more at http://news.xbox.com/2016/08/10/gears-of-war-4-pre-order-bonuses-detailed/#04L116ALGxu0PJ5c.99

According to the Gears of War 4 official site-

For a limited time, all purchases of Gears of War 4 include the entire Gears of War Xbox 360 library for free, all playable on Xbox One thanks to Backwards Compatibility! The Gears of War Xbox 360 collection provides you with four incredible games, from
the epic saga of the original Gears of War trilogy to the standalone story of Gears of War: Judgment.

Physical copies of the game will come with codes for each of the four titles to download via Xbox Live. For those who purchase digitally, your codes will be sent via Xbox Live message – we’ll be sharing more information on digital distribution closer to
launch.