Khazana Jewellery Private Limited - Cheating after money has paid

I had joined to pay every month gold scheme for ** months @**** Rs, and one month amount should be paid by the khazana as bonus. Now they are telling that only for silver and diamonds they will give that offer. At the time of payment they had not told that matter. And also they told that they while purchasing they will give gold for the price when we started paying amount for first month. We paid the amount in June ****.
They are very rude while we asking in shop.
Now they are telling they will give bonus only for silver and diamond.
For gold they give only **℅ making charge, it is so much of loss for me they are telling lies and cheating customers.