Flash Write Failure topic

I've just received another P7 to replace my broken and discarded device. The phone and HiSuite reports the device as being a P7-L10 build V100R001C00B121SP01. It is apparently "up to date". This surprises me as I know there are other builds.

I've managed to root the device with RootGenius and replaced Kinguser with SuperSU. However I can't flash a custom recovery! This is the output:

D:\Huawei2.3>adb devices
List of devices attached
7N2MWW1447002470 device

D:\Huawei2.3>adb reboot bootloader

D:\Huawei2.3>fastboot flash recovery twrp.img
target reported max download size of 838860800 bytes
sending 'recovery' (11256 KB)...
OKAY [ 0.437s]
writing 'recovery'...
FAILED (remote: flash write failure)
finished. total time: 0.452s

I've tried with twrp 2.7, cwm, and even a stock recovery. Same result.
The max download size strikes me as being way too big.
I've tried forcing an update with an L07 update app. But that just fails.

This phone lacks the ability to turn off 4G unlike my old L07 and I don't have the nasty "4G LTE" logo anymore.

I think the phone has been tampered with prior to my purchase as neither the phone or box match.

Does any one have any suggestions?