Medlife — Double payment taken against one order

I had placed an order #OR6214IKC-002A for certain medicines on 17th March 2021 and made a payment of Rs. 866.94. On the same day Medlife cancelled some of the items worth Rs. 476/- and refunded Rs. 476/- to me. The remaining medicines were delivered to me on 21st March 2021, but the delivery guy claimed that it was a cash on delivery order, and made me to pay Rs. 436/-, which I complied. thus, there was a double payment of Rs. 436/- to Medlife. I have called up and written Medlife several times during the last one month, but every time they are saying they are looking into the matter, but I have not received any refund till this day