Punjab National Bank — online refund dispute

I placed an order amounting rs. 2596 with myntra on 15th july (This was a collective order of four separate items: rs 576 + 912 +286 + 822). I canceled the order on the same day and received the refund amount of three items out of the four (Rs 576 + 912 + 822). As claimed by the myntra support the refund for amount rs. 286 was successfully processed long back (Along with the other refund) and i was supposed to get the amount by 23rd july, but i haven't received it yet. I tried lodging a complaint with the cgrms form on the pnb website but the link does not work. I contacted the pnb customer care with the provided bank reference number:[protected]As provided by myntra) but the customer care executive bluntly refused to help as he said the bank reference number is of no use and nothing can be done with that number. And the myntra people are telling me repeatedly to contact the bank team with the ref. Number. Please help as i dont know what to do.