Are developers required to provide contact infop

Having problems with game app, can't contact developer, are they required to provide some manner to communicate? Game is Jackpot Party Casino, PhantomEFX is developer, every link claiming to be customer support seems to be an exercise of patience & no way to contact. Read their reviews posted by 100's of other users complaining about the same issues. Game malfunctions, wins are not being added to bankroll (I have screenshots), in app purchases not being credited, the list goes on... And NO customer support. What other options available? Someone has to be able to contact them, who & how?