Myntra.com — refusal for exchange

Address:

Mumbai City, Maharashtra, 400016

I had purchased park avenue shoes from mytra.
Due to fitment issue, i asked for a change in size the same day. I have original bills tags however due to unavailability of box the company refused to accept the exchange.

The box which was received was in damage condition hence was discarded. But the company blantly refused.

I expect exchange of size from the myntra.