You'd better go to the bookstore and explain the situation to the boss. If not, add some money. Otherwise, few people will send it in mp3 format. That would be much easier. Just tell the shop owner to change it for you or send it to you in mp3 format.

If it is a CET-4 original title, you can ask your classmates to copy it. If it is a simulation question, you can go to the bookstore and say that he bought the book and ask him to correct it.