A chargeback transaction happens when a survey that you completed gets invalidated after you have been credited for it. Chargeback transactions are always negative because they "reverse" a positive survey transaction. Chargebacks are final, we can't undo them. You will need to contact the corresponding survey provider if you believe that a chargeback is unjustified. Please note that too many chargebacks can lead to a frozen account balance.
Let's say you complete a survey that is worth 5,500 points. After you completed the survey, the survey provider sends us a notification about the completion. At this point, we assume that we will get paid for the survey, so we credit your account with 5,500 points.
But a few hours or days later, the survey provider finds out that something about the survey that you completed was not valid. It might be that you used a VPN, multiple accounts, or that you used fake information to complete the survey. So the provider sends us another notification that tells us that the survey has been invalidated and we won't get paid for it. At this point, we will create a chargeback transaction that removes the 5,500 points from your account. That's because if we don't get paid, we can't pay you either.