Amazon India — refund not found for order no[protected]

Address:

Kiet group of institution, Meerut road (NH-58) muradnagar, Ghaziabad, Uttar Pradesh, 201206

My name is piyush, i ordered a phone samsung m30 from amazon on april 2 order number:[protected]. Few hours after successfully placing my order i got a mail that my order has been cancelled and my amount will be refunded to original payment method. Later i got on more mail that refund of amount of rs 14989 has been refunded with refund reference number[protected] and will reflect in my card till april 8, 2019. Till date i didn't get my refund and on contacting amazon customer executive they said that the amount has been refunded and contact to your bank regarding this. I called my bank customer care and they said they can't provide any help through refund reference number. I mailed amazon several times regarding this and only i got to hear is that we have refunded the amount contact to your bank, amazon people also said me to fill charge dispute form and when i went to bank they said they don't have any such procedure and amazon people are blufing on you. I'm very upset due to happening of these things. I have to buy the phone but i can't buy because from last 20 days they are not providing me the refund. Kindly provide me the proper solution.
My amazon i'd :[protected] and mail i'd [protected]@gmail.com.