Completely reset mobile phone (defective software)?

Unfortunately, 2 days ago my Huawei p7 (lite?) Adopted. After a crash, it went into an endless restart loop and there was no way to turn it off / start. I brought it to one of these "hand-setters", but today he told me that there was nothing left to save and the mobile phone was completely defective, I should send it to the manufacturer with proof. Unfortunately, I used it when murrad-Laden next door bought (as if the ne original bill has).

Now the question is if it is possible somehow to play a new android software on it, put it back or somehow something. It can't be that with intact technology only the software can do a total irreparable damage. The storage medium, etc. Is still running.

I have a Win10 Pc and a USB cable to connect. How can I get new software (by the way, there's a weirde serbian android software version with other menu orders and a few errors) or can i somehow share a reset with existing software without using the mobile myself?

Ps: no operation is more possible even the boot mode via power + vol. Button is not accessible.

I hope someone understands my problem and has an idea what I want

The reasons for defective hardware can only be fixed by the manufacturer. Or. The loop must be traversed point by point to find out where the problem is. In most cases, this can be done by the manufacturer himself, through the warranty offered.