The Freeview EPG (Electronic Programme Guide) which was provided by a company called ""4TV"" ceased transmission on July 1st. This means that PVRs such as Inverto, Thomson DHD4000, various Digifusions and one Sony model no longer have an EPG - just ""now and next"".
This problem seems to make them ""not fit for purpose"" under Trading Standards Guidelines so it may be worth contacting your retailer to see if they will provide a pro-rata refund. As electronic equipment is expected to last typically six years then, if you have had four years' use, you could expect a refund of as much as one third of the purchase price. (This would be the sort of award that a small claims court might give, so many retailers could ""stump up"" without much argument.)
However, you should seek legal advice so you should consult your local Trading Standards and/or Citizens Advice Bureau if you are affected by this.