Hi @Anonymous User
Didn't realise Argos was still selling the NowTV Entertainment Gift Cards, where i can only see the one week Sports Pass Gift Cards on their website for the last couple of months.
What's the error message when you apply the NowTV voucher code on the back of the Gift Card ?
Have you tried a different internet browser when clicking on the blue "Apply Voucher Button" next to the Entertainment Pass under My Account > Vouchers & Passes whilst logged in on here ?
Assuming you don't subscribe to either BT TV with any NowTV bolt on package or you have an existing Entertainment deal via Vodafone ?
Also, if you have a NowTV Box / Stick, Games Console, Smart TV with the native NowTV App, have you tried to apply the code via the NowTV App under the My Account section on your playback devices.
If no joy, jump over to live chat for assistance & help.
You will find the chat button on this link page below.
https://help.nowtv.com/article/how-to-submit-a-complaint