Fedex — Cheating me of Customs duty already paid

The AWB NUMBER for a package my the USA IS[protected].
I paid customs duty on 11th March and sent them all bank reference number, screen shot of payment made and bank message that money has been credited to fedex .The amount was rs 2200.

They still claim.they didn't get money and I keep chasing them but their standard answer is they have not received it.

my bank says it was credited on 11th.

there is zero support from the FedEx team to try and resolve the issue.