Refund

I purchased medicine from Vasan Medical. At the time of payment, I was charged an amount higher than the price that should have been billed for the medicine. I raised this overcharging issue with the shop and asked them to return the excess amount collected from me, but the extra money has not been refunded to me so far. I request that Vasan Medical refund the excess amount charged to me for the medicine at the earliest, along with a proper bill showing the correct price.