I don't have a problem now - it's just that it was so long ago that I registered my old phone and iPad that I hadn't either remembered or noticed that you now have to register them for the sky stuff as a separate item. Thankfully, if you get onto the 'fault' (??) team they will help you and even reset the number of changes you can make. I still find the limiting of how many changes you can make, while probably there for some reason to do with royalties or whatever, very intimidating since getting it wrong somehow can count against you.
Also, I found it confusing that you clear the entries on a PC but create them by logging in with the device. I assume that if I went to the appropriate website (and that isn't easy, at least for me,) to find on your main site I could have done this from the iPad as well.
It is also very odd that all of my browsers tell me that this action is not compatible with them but they all work. I tried Explorer, Firefox and Chrome.