Shopify’s Fraud prevention app is worthless. It does not actually “prevent” anything. It runs some filters to help identify orders that may be fraudulent AFTER they are placed. Thus, you will incur the credit card fees which the original poster is complaining about.
I just had a “customer” from Miami try 19 different credit cards unsuccessfully before finally getting one to work. Now I get to cancel the order and eat $40 in credit card fees on a $900 transaction. How this system allows that many failed attempts before automatically blocking the IP or something is beyond me. Shopify clearly doesn’t care or they would put more effort and thought into that app.
Anyways, enough ranting. Anyone know of a way to prevent this kind of stuff?