........even changing the atty it still leaks......................
Did you try using a different tank, such as a prefilled one that came with the kit and the 2nd atomizer? If the hole inside the tank lid gets damaged, such as being enlarged to much, then the spike from the atty will not get a good seal and this can also cause leaking. You could have a defective cart. Also make sure you are pushing that tank on as hard as you can until it can't be pushed no more.
So before you use the flooded atty again, blow it out real good and clean it with q-tips or paper towels to get the liquid out. Also around the battery and atty connection area. Then try a new tank.
So far I've only read of one person that got 2 bad atty's with their kit.