Welcome to Android Central! So was this a used or refurbished phone? A "mobile shop in a box" doesn't sound like the most reliable place--it sounds like they may have sold you a used phone, which can be a problem if it was rooted and modified by the previous owner, which then possibly caused these problems. What's the shop's return policy? If you just got the phone, it seems that you ought to be able to return or exchange it.
My HTC one M8, bought new two days ago from a mobile shop in box, worked for eight hours after all updates, now keeps restarting and can't get to the main screen, I have'nt even touched the settings.
The options it gives me is
I have tried all of these and none of them solve the issue, even HBOOT/factory reset, this didn't work.
Help, five days without a phone, getting withdrawl
P.S. didnt have an issue in three years with my galaxy s2!
If it says tampered, it means something was unintentionally changed at the very core of the software installed on your device (kinda like the bios). Go into fastboot mode and connect it to a PC. See if the phone changes from "fastboot" to "fastboot usb". If so, that will open more doors to find a fix for your device.