Got Scammed at Kalyom Jewellers

So I usually do Jewellery Purchases at Tanishq or GRT. Visited the Velachery Branch of Tanishq and GRT, but couldn't finalize the designs. Anyways, decided to visit "Kalyom" Jewellers which is just few meters away on other side of the road. As soon as we entered and started looking for the jewellery in question, were informed that there is a January discount going on for making charges, 25% off. So the jewellery in question had 13% making charge, and after discount it will be 9.75%. Sales person said this, that it will be 9.75% after discount. So we went ahead with the purchase. However, they asked me to pay higher amount than the quoted price. When I asked about the difference, they immediately reduced the amount and asked to pay almost same as the quoted price. Said they forgot to apply the 25% discount on making charge. They didn't show me the invoice that time. After the payment, they checked the weight in machine and asked me to sign the invoice. They again didn't let me see the invoice and immediately packed it in envelope and gave. Okay my mistake. After reaching home, I had a look at the invoice. They had added an insurance charge of Rs. 1458! And there was a insurance certificate inside quoting the same price. At no point did anyone inform me about it or took my consent. Although I paid close to the quoted price, but they had somehow inflated the quoted price to adjust for this insurance cost! I immediately called them and enquired about it. They started justifying the price, completely ignoring that it is under "insurance". Then they said will check with manager and call back. When they did, they said the making charge discount on my jewellery was only 20% and not 25%, that's why they have added the 1458 and Invoice is correct. I insisted that I was told it will be 9.75% exactly and the amount is clearly mentioned as Insurance amount. They kept trying to gaslight me. The system generated invoice has clearly given me discount at the rate of 25% on making charge. And Clearly added "insurance" of Rs 1458. They are not the same thing!! I threatend to file a complaint and they finally caved. They asked me to come and they will "explain". I didn't budge and requested refund through original mode of payment (card) or via UPI. Finally the sales person whose name appears on invoice sent me the Insurance amount via UPI. They knew what they did. They were all involved in it. Just trying to scam customers who don't check the invoice. Oh not the mention we don't get to look at the invoice carefully till it is packed and given inside an envelope (inside a bag inside a bigger bag, now I know why the free goodies). Normally people won't open 2 bags and the envelope then and there after shopping for 2-3 hours just to check it. But lesson Leaned, I should have. Unethical and illegal on their end, carelessness on my side. They were involved in previous scamming controversies as well. Guess they haven't changed. Avoid this "Kalyom" Jewellers if possible. Edit: TLDR Added Insurance charges without consent, claimed it was extra making charge when caught, refunded when I didn't fall for their lies and scam. Edit 2: Yes it is the famous jewellery store chain you are thinking about!