Sm-g928f No registered on network

[alex alex12]

Hi everyone,
I have an Samsung Sm-g928f and I can't make phone calls. It said "no registered on network".
Till now I tried:
-Factory reset
-New software from sammobile
-Root + Xposed for changing IMEI. My new IMEI is 123456789012345677/1

*The IMEI from the back of the phone was not the same with the IMEI from the software. I took the phone second hand, maybe the person who has the phone before me tried to unlock it or something...

Any solutions?

Sorry for my English

Thank you!
Have a nice day.