Hi again, @Boomerang1 . I’m sorry to hear 2Checkout has made this change, thank you for sharing this information though! It’s certainly disappointing that they no longer will process Mastercard and Visa directly through their gateway; I can see how this would be frustrating for both you and your customers.
In terms of another gateway to use instead, the ones that are integrated with the Shopify platform and available in Thailand are listed here. Although I am not familiar enough with external gateways to confidently make a recommendation, I believe Skrill processes Visa and Mastercard through their gateway. Therefore, I would start by looking into them as an option.
What types of products do you sell? Another consideration, depending on your business type, is to include Sezzle as a payment option. Sezzle allows for payments in installments. This can be appealing to customers, particularly with higher value orders, due to not having to pay the full amount immediately, but instead being able to spread the payment out over time. If this sounds like something you’d like to explore for your business, there’s an interesting article on the Shopify Plus page called Reduce Abandoned Carts with Buy Now Pay Later that gives some more insight into this strategy.
Hope this helps! Let me know what you decide to do.