Great App but doesnt last long

If you play this game free to play you have a great experience in the beginning but eventually you finish the story mode and run out of a way to get dragon stones(gems) to summon characters. Ive run into this problem and the only way for you to get dragon stones is to do events and once you complete them the first time you cant get dragon stones from them again. Like I said Ive run into this problem and for me the only way to get dragon stones is to do an event that is way to hard for me or to buy them. Do not get this game if you are going to be free to play.

SamuraiKiller1 about DRAGON BALL Z DOKKAN BATTLE, v3.3.0