No labor contract was signed, and the salary was discussed orally, just like in the recruitment brochure. I deducted hundreds without prior notice. How can I get it back?

You didn't sign a labor contract, and the salary was discussed orally, just like in the recruitment brochure. You deducted hundreds without prior notice. Although you haven't signed a contract, it's already a de facto employment relationship. If you want to save salary information, the employer can't deduct money without proper reasons. You can complain to the labor inspection bureau!