Definately VAT on UK accomodation except for small B&Bs etc. which don't do enough business to go over the VAT registration level. I'd agree that it should have been 15%.

BUT if you were quoted an inclusive price when you booked, which they charged, and have just noticed the VAT breakdown you won't have any claim because you accepted the inclusive price for whatever it included. Unless you booked months ago before VAT was cut and the price specifically said "inc. VAT at 17.5%", then you may have an argument for getting the 2.5% back.

The VAT on "holidays" is to do with package tours. As I understand it there's no VAT on the service charge of the package (ie the admin costs of the operator putting the package together) but you may be paying VAT on the accomodation without seeing it listed, possibly to a foreign government at their rate. There is no UK VAT on flights and trains however you book them.