Hello! 

Have you been a part of some other Combine that reached this achievement earlier?

In such case, you will not receive an individual bonus. It is added only once even if you change the Combine and reach the same achievement again.

Another thought ..On the Combine information page, in the list of Combine achievement medals..the above reward would have a littte ( ! ), located beside it..You will have to click on that little ( ! ) in order to claim the reward..but as stated by our Admin. you can only claim this 1 time regardless of your Combine affiliation at the time