Amazon.in - Not getting legitimate refund

I have purchased two Jeans @Rs. ***/- for my ** yrs old kid vide order ID ***-*******-******* on *st January'**. I received the item on *th January'**. After opening the parcel, I noticed that the seller sent me one Jean of size **" of the same brand. The fact was instantly intimated to customer service. They convinced me that there is nothing to worry and advised me to generate a return request. I act as advised but in next day i.e on *th January'** delivery agent came and refused to receive the item stating that in their system two Jeans have been seen although I was returning one. Then again I talk with customer service and they told me that the problem would be resolved shortly. Accordingly the delivery agent came on *th January'**** and received the item. Now mean time the involved amounts refunded in two parts; *st initiated on *th January'** and *nd initiated on *th January'**. The *st amount is credited to my account on **th January'** but the rest amount is not credited to my account till date. I have talked to Amazon customer service executives and even team leaders several times but every times they told me that they amount has been refunded from their end and gave me false assurance that the amount will be credited with in *- * business days. But till now the amount is not credited and even they could not able to provide me reference ID pertaining to refund. In consequence of that I become fed up with worthless customer service for their blathering and looking for your kind help to recover my hard earn money.