Foreign Exchange Management - Question and answers

We've been using a standard payment gateway that applies fixed exchange rates with high fees, leading to customer complaints and lost sales. I've experimented with integrating APIs from providers like OANDA for live rates, but the implementation is clunky and doesn't account for rate volatility over time. Also, we need to handle refunds and chargebacks in different currencies, which adds complexity. I'm looking for a scalable solution that balances cost, accuracy, and ease of use.