I'm sorry you've had difficulties in claiming your BT Rewards Card. I've checked the terms and condition for the BT Rewards Card for the 6th of September on BT Rewards Card, which states -
SIM Only plans
Family SIM plans
What package did you sign up to on the 6th of September?
Thank you for posting back. If you send me in your details I'll be able to get this investigated.
Please can you send me in your details using the "Contact The Mods" link found in my profile?