Why has my phone stopped responding?

[Windows Central Question]

why my phones stop responding

hy i have bought new lumia 640 xl .it stops working while i try to call someone and
sims doesn't work it says switchoff but network are full please help i happens 5 to 10 times a day and i have to remove my battery to make it work again

 

[SteelSteve]

I would say try a factory reset, and if that fails to resolve the problem you may need to contact Microsoft to have it replaced as this is not normal.