why no extra help

When I logged into the game and played the level more than once, a super hard level but that's relevant just more annoying, I had the chance to get upto five extra bubbles when I had run out however without taking that option as I knew I need ore help than that I carried on with the level but for some reason the option to get the extra bubbles at the end disappeared and not for the first time but now that I'm getting bored with the level I thought I'd ask the question though please don't tell me it's random, I know there is a point when you don't get the option as you used that option up but to have it taken away without using it is very unfair and I want to know why it is happening.