Don Jose has posted a method above that worked for me. Interestingly not only did it fix Destiny but all of my achievements from Tomb Raider have just popped up too. Again showing the issue most of us had is a MS issue. If it doesn't work for you make sure it's not a problem with your ISP, that your Gold hasn't expired and that someone else isn't using your gamer tag. If the fix does work for you write a nice apology to Destiny for your mean words! Haha Seriously though hope you fix it!