Are you sure the oil and gas positions you trade are non-expiring? CFDs for those products typically expire ahead of the related futures contract. That's probably why you haven't found a website comparing swap rates for oil and gas.
Could you please give us an example? FOREX.com updates the rollover rates on our our platforms regularly. If you believe we made an error, we would work to address it ASAP.
Note: Contracts for Difference (CFDs) are not available to US residents.