First, check that you have won the achievements locally in your achievement application. Achievements that have unlocked will show there. Depending on your settings a notification may or may not have popped up.
If the achievement shows as locked there, you haven't met the requirements. If it shows as unlocked but you were not awarded with it on your profile then Live hasn't registered it yet. This may be due to Live having issues (currently the case) or due to synchronisation issues which crop up from time to time.
Due to the latter, people have reported achievements unlocking many hours or even days after unlocking them locally. If you unlocked them locally but don't want to wait, contact support. I recommend chat support (Make choices until you get to the third step and choose chat support) as they are quite quick an can help you immediately.