No Service Iphone SE with weird Black Triangle on the signal. Cannot Activate it.

I have an Iphone SE and suddenly one day the phone rebooted itself and put me on the recovery screen. I went to my PC and restored my iPhone. After that i could not activate my phone because it says a weird message on iTunes.

and on my phone i see a weird black triangle on the signal side that i have never seen before.

Can anybody help me? I don't know what to do.