Need ZTE z830 firmware DFU

ZTE Z830 Compel* dead in DFU recovery partition corrupted
please help me for that

i had one zte z830 running on 4.4.2 android version

i trying to root it

by kingoroot.apk it was rooted but (temporary) when I restart it so root was removed so I try to write TWRP on it from twrp apk but accidentally i flashed another phone twrp from twrp apk after that it was stuck so I restart it and it was ok then I do factory data reset from settings after that it was rebooted and after AT&T logo only red light with dfu mode

Now whenever I power ON this phone it start with AT&T logo and then red light with DFU mode

please help me if anyone can plzzzzz

one more thing it is successfully going to FTM mode

in FTM mode computer detected two ANDROID drivers
1 is ADB debug driver

when I type adb devices in CMD it gives me (? device)

adb shell also connected

I think recovery partiton was corrupted

anyone tell me how to recover this phone how I write recovery img or how I postpone this factory data reset

Shahzaib Jahangir