Regular institutions can retire within a specified time. After that, they can negotiate according to the situation. If you can retire, you can complain to the local labor and social security bureau.

In practice, since you gave the money to others, people will definitely want to find some reasons to deduct a little from you. If you encounter something good, you should retreat more, and if you encounter something bad, you should blackmail more. Anyway, they have the money, and they have the initiative.

Litigation is time-consuming and laborious, so they will seize this point and cheat you a little, so keep quiet before asking for money and decide to refund it. Just call them and make it clear. Be polite but don't be supercilious. The call must be recorded. From now on, the more evidence you can get, the better, and the better for you.