I'm a new merchant and just had to deal with a large chargeback.
I lost the chargeback dispute with the bank, even though I spoke to the customer on the phone before processing the payment and confirmed by voice that she wanted to buy it, and all the details of her payment method.
This just feels like fraud.
Can I sue her for the amount of money I'm out? Is there some kind of app that can help?
Depending on the amount of the lost amount of chargeback, pursuing legal action might not be worth your time, effort, and money spent dealing with the issue that can otherwise be better spent on growing your business. The chances of you recovering your money are quite low and almost impossible since the Banks have made their final decision on the case. It's very difficult to appeal a case if the original account holder's CC was indeed stolen and used by a third-party bad actor pretending to be the original buyer. When calling a customer, You have to be a loss prevention expert to pull information out and make sure the buyer is a legitimate one.
Learn from this bad actor and be sure another incident like this does not happen again by protecting yourself with a simple app like Shopify's free fraud filter app or if you need a more sophisticated system, then it's a good idea to invest in a more advanced fraud prevention system like our app, Beacon (link below) which cost only 0.03 per order that allows you to track suspicious customer behaviors and flag it.
Also, consider applying some settings to your Shopify shop to better protect yourself by reading this article I wrote on this very topic. https://medium.com/@jason_80572/how-to-configure-your-shopify-settings-to-better-reduce-fraud-orders...
I hope this helps you a bit.