Punjab National Bank [PNB] — Refund from online purchase

Address:

Raipur Chhattisgarh

I purchases a POCO m2 pro phone from flipkart on 30 november 2020 and paid 13999 rs from my debit card. but the order was cancelled on the same day and now flipkart is saying refund has been done. I didnt receive any refund so flipkart told to contact customer care and raise charge disput. I contact PNB customer care, they said there is no such thing as charge dispute, and the people in the bank branch also said this. The customer support and behavior is very rude, their website isnt functioning properly so I couldnt file a complaint online, and there customer helpline people cut calls as they please and are very rude and provided no help.
I have been struggling to get my money back, flipkart only gave a reference number, but bank is refusing to take any complaint.

Refund reference - 17203010335047960396484
Amount - 13999 rs
Date - 30-nov-2020

I do not know what to do, I feel cheated and harrassed. I have been struggling to get my money, the stress made me unable to properly concentrate on my exams too. I had to visit my bank branch at least 6-7 times and no help was provided except they sent an email and no response. I am really troubled for this kind of behavior and lack of support, I wish to get my compensation for all the trouble as well the refund amount as soon as possible