a hemingway: OK, you need to tell us were you are (postcode) plus what equipment your using (aerial in roof, etc), other wise we have no idea if its your location, a fault with your equipment, mistuned TV, etc. If you need Freesat, then thats fine, but at the moment we have no idea.
No, you cannot claim any discount. The pensioner deal to get you digital TV was just for switchover, and just to get you digital viewing, no more than that. After that its up to you. I have no idea if benifits do allow you anything, but I doubt it.
If you have a TV set that you watch programmes on, then you are already watching digitalservices. If you are watching Freeview via a conventional aerial, then that is digital already. If you are watching Sky services, they have been digital for many years.
If you do not have a TV set at all, then all modern sets are capable of receiving digital TV with a suitable aerial for your location.
Jeanette: The question has been asked before, and the answer is no. Best suggestion is to check what connections are available (dish, aerial, cable), and perhaps work out the the most cost effective answer from there.