Worked it out, the plug is a tiny bit different. Its black, mine was yellow. My plug goes into the new one, but doesn't click in. So i need to call up on monday and get an exhange/refund for the part.
I have to change the seat belt over tonight for a road trip in the morning. I have got a second hand one from a wreckers. There is a airbag sensor on the seatbelt. I have only a drivers steering wheel airbag. Is there any special procedure to follow when pulling the old seatbelt out, and installing the new one? Thanks in advance!