Hi Fruit Cake and welcome to the site - after so long I doubt you could take it back to the shop you got it from. I don't know if it would do any good writing to Transworld, Terry's publishers and seeing if they could replace the copy. That's assuming that the pages are missing due to a printing error.
Wyrd bið ful āræd.
"Coffee. The finest organic suspension ever devised. I beat the Borg with it."
- Capt. Kathryn Janeway