Kalyan Jewellers — Itching and skin rashes due to gold chain recently bought bought

I purchased a gold chain on 20 January 2023 from Kalyan jewellers Dwarka sector 12 showroom based in New Delhi. Since the day of me using the chain I started having itching and rashes round my neck. On the second day i removed the chain and applied some dusting powder and rested for few days. When the itching and rashes subsided i wore the chain again, the same itching came back. I went to doctor and he suggested me to remove the chain and check if any reaction. I was completely fine and the rashes went away. Again on 5 March i wore it while i went out and wore it overnight, to my surprise my whole area of the neck where the chain was touching has all been swollen and it turned dark and more itching.

I need a customer support in this matter as I am surprised as to how such a renowned Jeweller like Kalyan jewellers has such faulty jewellery.