Actually, the publisher (from Canada) asked, begged, and pleaded for the buyers to return the books. They offered some fancy, expensive, gold-plated thing that was autographed by JK Rowling, and I think they were guaranteed to get the books first thing on release day. The publisher wasn't mad at the people who bought it and they couldn't legally make them return the books.
The store, however, will not receive any new HP shipments of both this book and the next one, and they will not get anything released under teh Scholastic/Bloomsbury banner either.
That is a hefty price right there!