samsung GT-S7710 unlock no work

hi
my samsung GT-S7710 ask unlock code after unlock
someone has an idea of the probleme ?
and factory code said "echec verrouillage "

log below

Operation: Unlock
Selected model: GT-S7710
Software version: 34.11

Waiting ADB device... OK
Reading phone info...
Model: GT-S7710
Android version: 4.1.2
PDA version: S7710XXANE3
CSC version: S7710FTMANE1
Phone version: S7710XXANE3
Product code: GT-S7710TAAFTM
CSC country code: France
CSC sales code: FTM
Phone SN: RV1F636C8BY
IMEI: 352735063178383
HW version: MP 0.900
RF cal date: 2014.06.25
Chip name:
Modem board: DB8520H
Checking Super user right... true
Reading data from phone... OK
Analyzing SEC file... OK
Bypass MSL... OK
Unlocking... OK
Rebooting phone... OK
Unlock done

Done with Samsung Tool PRO v.34.11

no work :(

phone ask unlock code again ....