How to change the duration of a movement with count- Swift SpriteKit?

In my game, there's a class for a "wall" that's moving to the left. I want to change the speed of it based on count i that I added to touchesBegan method:

override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent {
    count++
}

func startMoving() {

    let moveLeft = SKAction.moveByX(-kDefaultXToMovePerSecond, y: 0, duration: 1 )

    let move = SKAction.moveByX(-kDefaultXToMovePerSecond, y: 0, duration: 0.5)

    if(count <= 10)
    {
        runAction(SKAction.repeatActionForever(moveLeft))
    }
    else
    {
    runAction(SKAction.repeatActionForever(move))
    }
}

but it's not working. Can you help?

via Chebli Mohamed