The gold price charges bought in the golden shop are inconsistent with the price.

I spent a total of 2656 yuan in the gold jewelry I bought on Yu Jin Jewelry on February 14, 2018. Among them, the necklace bid price was 1105 yuan, and I received 1150 yuan. I only found that I received an additional 45 yuan on August 23, 2020. I went to find it wrong. Is this price fraud? How should I protect their rights?