[nifboy]

1) Select model S6500
2) Tick unlock
3) Connect phone powered on with C3300K UART cable (via com port).

Here operation log:

Count supported models - 319
Reading Phone Info... OK
Model: SGH-I827D
Country Code: TLS
Cal Date: ªU
Factory SW: I827DTLLE4
Unique Number: CSJ08970027C45F
Memory Phone: ªU
Phone S/N: R21C617QV8
Build: 76XXU-USMSKRLYM-109806
IMEI: 3530520
PDA/CSC Version: I827DTLLE4/I827DOYBLE4
Phone version: I827DTLLE4
Phone HW: REV1.0
Cal Date: 2012.06.08
Read Security... OK
Bypass MSL... OK
Unlocking ... OK
Done with Samsung Tool ver 12.7

Then you are out of luck, anyways you can try to:

1) Use 00000000 as unlock code
2) Reset phone and then try procedure again