If they were actually marked as FAT quarters, it would be a kindness to let the shop know they were cut incorrectly. They may have had someone cutting them that didn't understand. If they were marked as quarter yard cuts, then that's a different story & you received the right item.
There are lots of patterns out there that use fat quarters and have you cut pieces that are wider than the 9" you have. If it's a new shop, this might kill business!