Hi @Dave1w
Are you on a current Entertainment offer with 30 days or more remaining which will prevent this offer working on your account ?
If not, maybe try another internet browser when clicking on the link or when clicking on the link see if there is a NOW voucher code embedded on the url address bar when clicking the link.
Should there be a voucher code embedded when clicking the link, it will usually start with NOW***********.
Copy the voucher code down and apply it under the Apply Voucher button link below the Entertainment Membership on your online account.