This negative payment adjustment is for the Stripe Dispute and Processing Fees* incurred from our payment processor, passed to you as covered in our vendor TERMS.
Chargeback fees occur as a result of customer(s) opening a dispute with their credit card company because their purchase either did not arrive or was in a condition that was unacceptable.
While we do our best to fight these chargebacks on your behalf, if we do not have sufficient evidence against the case (such as a valid tracking number for physically shipped goods) then the customer is refunded by the payment processor and a dispute fee is incurred.
Starting March 2017 we will be processing these fees monthly. Should you not have any purchase disputes, you may not see these fees deducted in the future.
*Stripe charges $15 per chargeback, plus a processing fee of 2.9% of the transaction amount + $.30. You can learn more about their dispute fees here: https://support.stripe.com/questions/how-does-stripe-handle-chargebacks