Landlord, if your ring is PT950, it is easy to deform, because its gold content is 95%. If it is a precious metal, the higher the purity, the softer it is. If it is 990, it is rarely set with diamonds. Considering the firmness of the diamond, 750( 18K) is better. General brands will have after-sales service, so it is best to negotiate with them. If not, go to the Consumers Association to complain. If not, go to Clety Jewelry in Tingluomei City, a suburb of the East Fourth Ring Road, which is a national chain. Their maintenance is free and the technicians are very skilled. I bought it there when my friend got married, and the after-sales service was very good. You can maintain it for free if you don't buy it at his house.