Myntra.com — return failed. now product not delivered back.

I ordered a pair of red-tape chinos worth rs717 from myntra on 24 june, order id:[protected]-5901203. The product was delivered on 28 june.
Due to size issues i wanted to exchange it with a smaller size. But due to the unavailability of smaller size i placed a return request on 30june, return no:[protected].
Due to the unavailability of pickup service for my product i had to self-ship it. I shipped it through dtdc courier paying rs170 on 1 july.
On 2 july i get the update that my product has reached the myntra return centre ie
Vector e commerce pvt ltd
(A/c: mirza international limited)
Dev niwas, k-2 block
Khasra no-819,
Behind maruti service centre,
Mahipalpur, new delhi - 110037
And my returnhad been put on hold for quality check process.
Later in the day i received an update on my email that my return request has been declined as my product didn't pass in the quality check process (Which wasn't possible as i shipped the product in perfect state with all the tags and original packaging in its place, they intentionally did this and i think they are trying to rob me). I talked to customer care that day and the they informed me that my product we be reshipped back to me and told me to wait for it and also assured me that i will get refund on the shipping charges as part of their return policy.
On 11 july i contacted the customer care again to get info of the product as i didn't received it yet and nor any update about the delivery.
They informed me that my product hasn't been shipped yet and noted a complaint against the issue and told me to wait for 3 days and informed me that i will get an update on the issue.
Again on 15 july around 11:30pm, i contacted the customer care and told me to wait for 24 hours and gave me the complaint reference number - in[protected].
Yesterday (16july) again around 11:30pm i contacted the customer care but they don't have any info on the status of my complaint and asked me to wait 3 days more.
I have waited long enough and they are just wasting my time and not solving the problem.
Please solve the issue and help me get my product back or refund on it and also the refund on the shipping charges.
Total amount - rs887
Order no.[protected]-590120
Return no.[protected]
Complaint reference number - in[protected]