Need SIM unlock code for NOKIA 610 NFC

I need your help please.
I have bought a NOKIA 610 NFC (RM-849).
It was fully functional and unlocked with WP 7.5.
I upgraded it to WP 7.8 with Nokia care suite 5.0 and now the phone is locked and asks for unlock code.
I dont want to pay for the unlock code again and I dont know where the phone was unlocked.

If some one can help me please :
OPERATOR : Orange France
IMEI : 353288051001646