how to fix unfortunately, system has stopped

[AC Question]

I have a SamSung Duos gt-s7562 with android version 4.2.1. I'm having serious issues with it. Its a brand new phone. Its a dual sim phone but every time I but both sim's from 2 different network in it, it says "Unfortunately System UI has stopped" and i'm only able to access one of the network. I cant access Sim Management on the phone either. when ever I select Sim Management it says " Unfortunately, system settings has stopped." what should I do? what is causing that?

 

[B. Diddy]

If it's brand new, I'd bring it back to the store and ask for a replacement.