Grt Jewellers — A purchase from GRT jewellers

Address:	GRT jewellers, Kamanhalli main road, Bangalore
Website:	www.grtjewels.com/?C=D;O=A

My husband had made a purchase from GRT jewellers online where they claim hassle-free return and exchange. they item was delivered well in time but the earrings had no closure at back of the hoop design so we opted exchange.
The store people were reluctant to attend a customer who can for Exhange of an online purchase. after a lot of hassle they agreed to entertain. but the billing they did where i paid GST twice, one in previous purchase and again for this exchange. Not just this for a gold weight difference of 0.43 gms, I had to pay 6760 rs. It was really horrible to purchase from GRT. I had several purchases from candare by Kalyan and that was superb. These people fool customers by claiming hassle free 30 days exchange.
Why fool by telling this when people in store are educated not to entertain online buyers?
Why to put 30 days barrier on exchange when paying the GST etc again one can exchange whenever they want.