@Anonymous User
There is a little black button under the battery lid on my remote that resets it; have you found such a button on yours (though it might be an earlier model, without) and held it pressed in for a bit?
If still no go, then for immediate use, try downloading the Roku Remote app, which will let you control your box from a smartphone or tablet, iOS or Android.
If this does not work, you may conclude the box is the problem.
If it does work, get a replacement remote from here, whichever matches your existing one:-
https://accessories.sky.com/catalogue/now-tv/all
Please note that I am just a customer like you, and my advice may well be worth no more than exactly what you paid for it.
