HELP. "No Service" on my iPhone 6 - iOS 8.4
I have this "No Service" issue on my iPhone 6 iOS 8.4 This happened 2 days ago, after my battery died (expectedly, merely a minute after it still has 1% left), I charged it until it's usable again. I noticed that it shows "No Service" on the upper left. I tried to put the "No Service SIM" on my other iPhone, which is iPhone 5, and nicely it has signal, definitely, I may conclude that it has no SIM issues, I tried to bring back it to my iPhone 6, sadly it still shows "No Service" I did so many things like Airplane mode on/off, manual selection of carrier, hard reset, Reset Network Settings, Firmware upgrade via iPhone 6 Restoration, upto the point when I erase all the settings and data, then restore it, still it shows "No Service". What can you recommend to me before I bring this up to Apple Service Center (that could be miles away from my house)
TLDR: My iPhone 6 iOS 8.4 has "No Service" after recharging it from an intentional dead battery (a minute after 1% mark.) I did many things like hard reset, restoration, and complete erase of data and settings. Still "No Service" HELP.
ADDITIONAL: I already did what Apple recommends me. -> If you can't connect to a cellular network or cellular data - Apple Support
iPhone 6, iOS 8.4, 3 months old.