Harman India — they didn't return my product.

Address:

R-10 SBI colony near resonance coaching mp nagar zone 2, Bhopal, Madhya Pradesh

I brought a earphone (Jbl t110bt) from myntra, that product is in warranty and as informed by your indian support i courier them to your service center but after that there is no follow up.
The courier delivered their on 14 october but till now there is nothing response from them.
When i call to your indian support they ask for irrelevant things like proof of delivery. As i don't have anything like that but anyhow i managed to get photo of entries that are written down by watchman there (Attachment is there) now your team denied that this is not proof of delivery.
Now what can i do?
My consignment no. Is bho[protected] which the 1st product that reach service centre in that day