Can,t log in to ag account in Monsters Den Chronicles, Kingdom Rush, GemCraft Labyrinth, and get premium content that already bought. Clearing cache, or trying another browser, or another computer dont solve the problem.
Best thing you can do is write a direct email to Justin from ArmorGames. He's the main person to deal with this sort of thing and should be able to help you the fastest! =)
Email him at : support@armorgames.com (fastest response) Or write him a comment : armorgames.com/user/jroyster22 (slower)
Some additional information on game login and save problems can be found in this thread.