Denying to Replace the ordered product which is been taken back from me

I placed an order on Yepme website for 2 shirts, 3 T-shirts, 1 trouser and 2 jeans on 12th sept 2014.

I received the order on 17th sept 2014. I faced a problem with the size of trouser and jeans so i called up their cust care who asked me to choose the other items in the same price so i chose two other items as a replacement for jeans and there was no replacement for the trouser so i asked them to refund me the amount.

They asked me to courier the items to their address : K-618, Rangpuri Ext. A-Block, Near Tata Telco bus service station, New Delhi.

They received the courier on 8th Oct 2014 but now they are saying that they will only refund for the trouser but will not send the replacement for the two jeans. I have paid Rupees 1200/- for the Jeans and now they wont replace it.

I have the courier receipt and the Sms details that will show how they are cheating on their customers.