This is a gift from parents to their children.
The conditions for the formation of creditor's rights and debts must be proved by sufficient evidence. Without a written agreement between you and an adult child, or other additional conditions for funding your child's university, it is difficult to form a creditor's right against your child.
Without any evidence, the court will not file a case for you.
In China, although parents have no obligation to support their children after 18 years old, in fact, most parents will contribute to their children's college education within their power. This is also human nature. Now that the money has been paid, there is no need to take care of it, even if the child does hurt his parents.