First of all, it should be clear that there is no such thing as "unfaithfulness" to your girlfriend. Because she is in love, everyone has the right to choose freely. You can only criticize her from the moral high ground when she cheats. Therefore, the bride price you gave her or the diamond ring necklace you bought has the right to get it back. Don't think of any bad idea to get it back, or you will take it yourself. If the bride price is large, they can be sued in court. The general court will mediate first. If mediation fails, they will be forced to pay back the money and will definitely get it back. As for you hitting her, it didn't cause any harm or disability at all. Of course, hitting people is always wrong.

Article 10 of the Supreme People's Court's Interpretation on Several Issues Concerning the Application of the Marriage Law of the People's Republic of China stipulates: "If the parties request to return the bride price paid according to the custom, the people's court shall support it if it is found that it belongs to one of the following circumstances: (1) Both parties have not gone through the marriage registration procedures; (2) Both parties have gone through the marriage registration formalities, but they have not lived together; (3) premarital payment, causing difficulties to the payer.