Bookstore return help...?

Hey, so i hav a problem... I bought 2 books from the bookstore, they're titles were "50 mysteries" n "50 ghost stories" n i dont like 'em at all...but the main thing is tht my frnd came over my house yesterday night for a sleep over, n she took off both of the plastic cover of the books... she felt sorry 2... n now i feel guilty for getting the books in the first place... i mean, i was rushing... i had 15 minutes n i bought another book along wid 'em... n i've finished tht one in a day... thtz the only book i feel satisfied wid... waddu i do now???...