Welcome to the Community, @Cday22
Just as a first port of call, can you please try opening the link for your rewards card via a different device or browser?
It's also worth giving the link below a try to see if it allows you to redeem via there, too:
Claim your BT Reward Card
If you continue to struggle from there, please give our team a call, and they'll be able to investigate this further for you 😊
Peter
