Restarting all the time

Xzasxz

It's getting worse and worse with every update. If, by any reason, I stop playing just for few seconds, game restarts.
Answer the phone - game restarts.
Switch to another app, just for quick check - game restarts.
Sceensaver turns on - game restarts.
Even when I start the game, it loads that long, that screensaver turns on. Then game starts loading from the beginning. It can be infinite loop.
Guys, this is MOBILE game. Why such problems?! Could You please concentrate on improving performance and stability BEFORE any new content?
My device is ASUS Zenfone 5, not the top technology, but more than enough for that kind of game.