Union Bank Of India — Haven't got refund in my account

My name is vishnu karthik and i have ordered "techleads 1045/1045r oem propeller multi rotor helicopter, black, set of 2" of rs.530 in amazon on 26 jun 2020 and after i received it, i have returned this order due to personal reason. Then amazon initiated the amount to my card but i still didn't get the money. Amazon sent this reference number 30005401910178180265253 and told me to fill charge dispute form but indian bank doesn't have such policy. So
Please kindly respond to this complaint it's very urgent. My card number is [protected]
Thank you sir