Dear Client, I am a Merchant exporter. I had lot of experience in International fund transfers.
Normally Banks will automatically charge wire transaction fees. But there is no way the respective banks ask for Western union money transfer fees, So probably that's a scam.
Kindly call up on your bank and verify the same at your end.
Also please go through this article which will be of a great help to you.
https://www.monito.com/en/wiki/bank-charges-for-sending-money-abroad

If you have any further assistance, Please get back to me.

Thank you
Warm regards
Parthasarathy