First of all, it is impossible to retreat. How can I return it after all these years?

If you still have your diamond certificate, you can change styles for free and make up the difference.

Chain stores all over the country can be changed.

If you can't find the certificate, you can only wear it. Diamonds without certificates are worthless, just like people's identity cards, there is no way to prove the information of diamonds.

I hope I can help you.