Myntra.com — misleading account shown payment and real accepted payment and refund

Under free shipping offer i ordered a dress which reflected the final payment values on account (without shipping charges) but when delivered they asked 150 more including shipping charges which is misleading, i accepted and paid for later to return it unaware of they won't refund whole paid value by saying shipping charges are not refunded by the customer care .that would hav been accepted if they would hav shown whole value vt Shipping(without misleading offer) in my myntra account and then charged that then subtracting the shipping charges that is accepted but myntra shown something thn charged something finally won't accept is very much wrong and disappointing.