How do you get past level 288 on best fiends forever. It has the electric bars on the right side of the screen & nothing can break through it & I need 12 purples to complete level & they are all behind the bars

This is level 288 I'm stuck on. When u blow up explosive it also blows up bomb at the same time & no more drop down. Does anyone know how to get passed this level. All my helpers are at level 13 at least if not higher. I'm playing best fiends seriously . Thank you in advance for any help. I've been stuck on this level for 14 days It very frustrating to the point I may uninstall the game if no one has any suggestions