We had a similar problem quite some time ago before where some orders were placed and were purchased with 2CO. Got the email notification stating that the orders passed Fraud checks and was safe to proceed with order. Then went and processed the orders and weeks later came back and told us that the orders was fraud. The orders had domain registration, etc that could not be refunded so we were out of that money.

Was a good lesson to use your own fraud protection, which is why we use MaxMind + phone verification. It will help you a lot to reduce/eliminate these type of issues in the future not just with this payment gateway.

As with any payment gateway, it is your responsibility to make sure the order is not fraudulent no matter which company you use to accept payment especially if you decide to get your own merchant account. You will get a higher amount of fraud with online as it's easier to do then in person at a store.