why is my battery draining so fast and gets heat while charging and even not charging too -950xl

It's been two months that i bought 950xl(single sim variant) and still using it. From my first day of use 950xl gets heat n it's battery 🔋 it's draining so fast. I update my phone to latest os version and even tried hard reset too but the problem is still going on. I haven't install so many apps neither using so many apps in background but still same problem. Microsoft is claiming it's battery 🔋 back up for playing video is 11 hours and music 75 hours in it's site but it's totally fake.

from Windows Central Forums //forums.windowscentral.com/showthread.php?t=455681&goto=newpost
via IFTTT