Use of 2 chocolate balls is only useful in certain levels, certainly not here.
Clear the middle column as fast as u can. When the time bomb started coming down, it will be easier to clear. Create as many combos as possible. Plan your moves. See which are the ones you need to clear. See where your candies are dropping into the next move or if you can anticipate further positions. Sometimes there isn't a need to use up your combo so soon. Position them to your best advantage
I did key is to get 2 chocolate balls together
Clear the middle column as fast as u can. When the time bomb started coming down, it will be easier to clear. Create as many combos as possible. Plan your moves. See which are the ones you need to clear. See where your candies are dropping into the next move or if you can anticipate further positions. Sometimes there isn't a need to use up your combo so soon. Position them to your best advantage
See how it is being done here
candycrushsagabylengguanho.blogspot.sg/2013/06/…