70% Charge S6E Dies Totally

Was surfing a basic page and bam all of a sudden screen goes off dead. No response to any combination of keys to soft or hard reset or leaving on power.

Returned to Samsung fixed but they never stated what the issue is.

Lost at data from the phone, that wasn't recently backed up !!!

Sent from my SM-G935F using XDA-Developers mobile app

my mobile dies

Gyus my mobile has very strange behavior . restarts without reasons, imost times cannot connect to wifi and other strange things . it got to a specialist and he said that probably is the battery . One else said it is the cpu and that its going to die .
I have it pure stock. no root no nothing. i wipe everything and reflash the latest rom but i have the same problems
can somebody help me?
thanks in advance loizos