If the replacement date of 15 days stipulated by the state has passed, and your ring has traces of use, it is difficult to replace it with a necklace with the same price, that is, the ring you bought at that time was about 5,000 yuan, so if you change the necklace now, the store may only be able to get a 20% discount, which means that your ring can only be worth 4,000 yuan.