Well, since he did want to find out something...
You would have to be re-added to the clan by someone with invitation rights in your clan. You're in another clan right now so either that's the original one or you randomly joined another one after leaving this one and your problem is solved already.
Secondly, this isn't really the place to ask this though but the support forum could be but is much slower. The fastest more appropriate place to ask would be to find an admin on the forum leaders page and PM them or go to the #support IRC and ask there and wait for a response from an admin or clan moderator.
Good luck.
Last edited by Foxy; Feb 12, 2014 at 09:17 PM.