Iphone 6 Plus is blokked

I am having much with my Iphone 6 Plus. It is doing all sorts of weird things out of itself.
It opens up App´s and even calls numbers out of itself, especially when it has opend WhatsApp.
I have tried almost everything I could think of and now I cannot even unlock. When I try after a long time and can get in, then all the Apps are locked. Also the battery does not load. Anyone for suggestions?
 
Back