Bought 10, 1st working perfectly, will try the rest as needed, thanks.
Other 9 expired "Sorry - this was a limited offer and you missed out this time." 
I have the same issue, brought 4 passes, first one worked, and the other three not valid
All of your codes are still active. If you have used a 1 week pass on your NOW TV account previously you will have to change the debit/credit card attached to your account to a card you have not used with NOW TV before a second code will work.
Since this disclaimer was missing in original post I can offer a refund.