Punjab National Bank [PNB] — refund for amazon

Address:

Muzaffarnagar, Uttar Pradesh, 251001

Sir i had cancelled an item that i paid online on amazon, they gave me a reference no-275314 and said that the refund has been iniated in my account but nothing has done so far, they told me that the reference no is generated by bank when your refund had process and contact your bank for further support but even my bank isnt replying with a satisfactory answer what do i do