GRETEL GT6000 Infinite boot

Hi everyone,

I recently bought a GRETEL GT6000 for it's awesome battery,
sadely this phone is hard to root.
I try many & many solutions but no one root the phone and now my phone is in infinite boot with message "Orange state you're device has been unlocked and can't be trusted Your device will boot in 5 seconds"
I can't connect to adb or fastboot, I can't boot in recovery (volume up and power), in fact I can't do anything.
I try to pull of the battery but it didn't change nothing.

The last thing I was doing before this, is to flash a custom recovery.img (made with both official rom and a TWRP rom).

I'm hopeless & I'll be glad if somenone have an idea to share it here.

Ricardo