Huawei — honor 8x/ device suddenly display problem automatically brightness low and many lines are there

Address:

Near amar talkies ward no 6 junnardeo, 480551

Please my device repaired or replace yesterday night proper working my phone's and suddenly display brightness low and display vibrate just 5 minute later brightness low and nothing recover.
I have messages hi care and service care answer is mobile restart and solve your problem but not solve this problem please help me this mobile is warranty period