Myntra Company - Return request declined citing quality issues despite there being none

Myntra order no.: *******-*******-*******

Issue: Return request declined for an unused/undamaged Adidas sports shoe. The reason cited was a failed quality check. But I haven't worn the shoes simply because there are fitment issues and it's impossible for me to walk wearing them. The tags are intact.

Action taken by me:
*) Tried returning the shoes for a refund. So as to buy some other pair of shoes with better fit.
Myntra declined this after recollecting the shoes from me, and cited a quality check issue. That the shoes had been worn (which isn't the case). Myntra then reshipped the shoes back to me.

*)Next, having received the same shoes again, I lodged a request for an exchange to at least get a bigger size (size **) of the same shoes. This time the delivery personnel himself refused to carry out the exchange citing the previous quality check issue, and asked me to get approval from the customer care.

*) Next, the customer care gave empty assurances of raising tickets for re-investigation. After waiting for more than ** days for the investigation to happen, I was intimated that they have concluded the investigation without even sending someone to verify the shoes' condition at my home.

This entire process of quality check and subsequent re-investigations was a sham and non-transparent.

Expected Resolution: Full refund of the amount Rs. ****.

PS: PFA pics of the product