Amazon India — refund return courier charges

I ordered a wooden lemon squeezer (order no. #[protected] on 25th July 2018. Please note that the return policy was not clear on the product page. I received this order on 27th July 2018. As the lemon squeezer I received was a very poor product with hinges rusted, rough, badly finished wood and was in an unusable condition, I applied for return on 28th July 2018. I got an e-mail that I would have to dispatch the product on my own. I didn't understand why I have to take the pain to dispatch the product myself so I wrote to the Amazon customer care on 29th July 2018. Some Mahalakshmi replied and requested me to courier it on my own and "assured" me that they will refund my return courier charges and I quote "Once we received your snap shot the return courier charges we will refund your return courier charges". As asked by this Mahalakshmi I dispatched the product on my own and mailed her the slip of the return courier charges of Rs 100/- on 01st August 2018. Since then a different person replies to my e mails and "assures" me that I would get my refund of return courier charges. But I regret to inform that till date I have not received the return courier charges of Rs 100/-.