Ebay recognizes it as delivered. The buyer can open a case under the EBay Money Back Guarantee for INR. The response to the INR case should include the tracking number, even if the shipping was purchased from Ebay. The seller will win.
If the buyer opens a credit card dispute aka chargeback, the result is not guaranteed to be in the seller’s favor, so there is a risk of losing, getting no Ebay fees returned after the refund, and a $20 chargeback penalty if the seller does not refund voluntarily and contests the chargeback.
Your math is right, but does not consider all of the common scenario.
Some sellers fight to the death to avoid a refund, others will refund if the amount is small, others will refund rather than risk losing a chargeback.
That’s why we business owners get paid the big bucks, we have to decide.