Medlife — not processing the refund amount even after taking the product back

I returned few medicines around one month back and they are not ready to process my refund amount saying their warehouse team didn't receive the product.
Everytime I am calling their customer support they are repeating the same words " our warehouse haven't received the product yet. Once they receive the refund will be processed"
I mean seriously ? It's been one month still the product didn't receive their warehouse? By one month it would have reached moon as well I guess.
If they misplace something that should not be a customer's responsibility but they are not ready to take the blame on them.