The game crashes during battles, opened shards are not giving any characters and the boss battle crashes but still takes a key!

Playing on iPad with the latest iOS (12.4?). 

Getting very frustrating as progression is impossible without new characters, if this is not fixed there is no point in playing.

Already lost about 30 characters including legendaries, 20 boss keys and uncountable battle crashes which take resources with no prize at battle end. The whole game is starting to fall apart at the seams.

This is not what i expect from a game, they should be enjoyable not frustrating to play.

Please fix these issues quickly so that I can continue to play, if not I will be forced to play other games and give my money to another software house.

All of the above issues have been reported by other players before so you should have a good idea on what is causing them, please fix or you may lose customers.

Thank you for your time in this matter.