If you can weld yourself, you can weld yourself again and use it.
You'd better go back to the place where you bought the silver necklace and have it repaired. For them, this is a very simple method. And if you buy it soon, you can ask them for free. If you bought it online, contact customer service directly. If the purchase time is not too long, discuss whether it can be exchanged. If the other party doesn't agree, then you can say that you pay for the maintenance and let the other party return to the factory for maintenance.
At present, there are still services for making precious metals such as gold and silver jewelry in the market. You can explain the situation to the master and whether it needs to be remake into a new style. If you are not at ease, you can watch the production process on the spot.