Just consider it cost of doing business and move on. You can also offer discounts for alternative payment methods but something tells me cards will be more attractive.

Yes, that’s pretty much how I look at it. And in all of our products I do everything possible to keep chargebacks to an absolute minimum, sometimes even making decisions that aren’t the most profitable from a business perspective.

When I look at some other companies, I often see all kinds of "shady" tricks that clearly boost revenue, but also inevitably increase the number of cases like this.