I agree, you can't end chargebacks on this category. You could maybe require a chargeback for 'i didn't buy this' to disable that card for that category (maybe that's a feature you want anyway?). You could maybe require enhanced authentication for this category (3D-secure??). You could charge merchants a higher fee and/or hold payments for a much longer time to avoid the need to pull the money back from the merchant. I think most chargebacks need to be started within 120 days of the initial charge, and it's fairly annoying to need to wait 4 months to get paid, but it's better than not being able to access payment methods.