In the Bitcoin network, we know there is no refund or rebate option. Once you send BTC to the wrong address, so sad, your BTC amount will never revert to you. Fortunately, BTCpay has just updated their server to 1.0.5.0 version which includes one of the most hottest and awaited feature i.e. BTC payment refund option.
BTCpay has its own open-source BTC payment processing software and the recent server upgrade includes notifications for the transaction status updates and streamlined refunds.In previous, most of the BTC payment software have push payment option which means users are allowed just to send the payment but now, BTCpay has made it possible to pull the payments and also there is refund option which includes, certain communications between sender or receiver to get full or partial amounts refunded to the original sender. Have a look at following photo.
References:-
https://decrypt.co/33812/bitcoin-refunds-possible-with-btcpay-server-update
https://blog.btcpayserver.org/btcpay-server-1-0-5-0