Unhappy [Q] [q] help me please

Hello everybody
I am a new member of this forum
I hope to get all help from everyone
I have a smart phone named SAMSUNG GALAXY S4 LTE-A SHV E330L
It ran on stock rom 4.3 (rooted). When I connected it to KIES, my phone informed : “ANDROID KITKAT 4.4.2”. I updaded online by kies, then I rooted successfully. However, after 2 days, my phone crashed suddenly. I checked IMEI which showed: null/null and it lost BASEBAND. Now my phone is locked, even that it does not receive sim card
I really hope to get all your help
Thanks for all