i have bought isen and iam vip yet it still says i have to unlock dragon raid
How did you purchase Isengard? Straight from the webpage with cash, or from the LOTRO Store in-game with TP?
If the LOTRO Store, did you purchase the Isengard full expansion or just the quest pack? If you don't have the raid, it sounds like maybe you just got the quest pack which does not include the raid or the instance cluster.
i have bought isen and iam vip yet it still says i have to unlock dragon raid
Apart from type of pack issues mentioned below, you need to be 75 and unlock it first through a quest line to Nars Peak (from memory). Then you'll be sent to find a map-kill an enemy near there to get it. Return the map and it should complete the quest and open it up.