Now TV have now admitted that if you have a running Pass of any sort, you won’t be able to get this offer. Try cancelling any existing passes you have, and then try again.
Be aware, if you cancel a Pass yourself it only cancels the auto renewal at the end of it's current period. The Pass will still be deemed as Active until then, so you are still likely to miss the BF deals. To cancel them immediately (Instant Cancellation) you will need to go through NOW TV folks via Live Chat and request it. They can do it in a matter of seconds. Then the BF deals should appear (worked for me yesterday). Live Chat is quite onerous and time consuming as you are dealing with an India based call centre (think TalkTalk if you've ever had the misfortune of needing to use their customer service). It would be much quicker if it was UK based but you can still get the result. You just have to be prepared to do the hard work. Not very client centric really.