Trouble applying for a clan.

I was recently invited to join a clan a couple times..and so i accepted.
But the problem is that it won't let me join, even though im a Sergent in game.

As i click "apply" on the clan page..it says "You must be level 4 to join a clan, you are now level -999" so I ignore that, then type in my in-game name..click submit, then it say's you must be Corporal to join a clan.

I have tried this on 3 different type of web browser's such as Firefox, google chrome..and internet explorer.

Please help me as soon as possible.

Ps: This has occurred on more then one clan page.