Iphone will not activate

Hi

I've had problems with my iphone for a few days now. Have an Iphone SE, cannot call or access mobile data. Up in the left corner, it is constantly searching. I have tried everything that says apple on "no service / iphone search", also with restore via iTunes. But this does not help at all and it announces errors under roads. I reset it and wanted to try again from the start, but It doesn't work, and i get the message on the screen when I want to activate my iphone - "Iphone could not be activated because the activation server is temporarily usable. Try prohibiting iPhone to iTunes to activate it or try again in a few minutes.

Hope you can help

And sorry for my bad English