I think this was to be expected soon as it was announced that it wouldn't be supporting NowTV Boost which is part of the focus for NowTV now. I am glad to see they have given people at least a month worth of notice so they can get a new device and are offering people a stick as goodwill.
NowTV have certainly been focusing on getting rid of the old platforms which I see as a good sign they have stretched themselves too thin. EE TV I expect will be the next one to go.
Try getting in touch with NowTV (good luck with that !)
the general email is ‘help @ NowTV.com’ or try the ‘chat’ option. The chat took me around the houses with no success so I eventually went via the ‘complaints’ route and got in touch with someone.
They say the sticks Are NOT a replacement but goodwill (only one offered to me) even though I (and many other people) have multiple white boxes. You may be able to negotiate a discount in a stick. I did that for my 2nd white box. Apparently they’ve been out for about 7 years!!