Hey there! Thanks for the post. As @Sify said, sometimes fraud refunds can put your account into the negative. We do our best to avoid this situation, but it’s a reality of doing business on the internet where identities and data are fluid.
Here’s what happens: Patreon will refund our portion of the purchase (the Patreon fee, any credit card fees, etc) to the owner of the stolen credit card. The creator is obligated for their portion as well, returning it to the rightful card holder. To be clear: that money was stolen and passed along under an illegal pretense. It does not belong to the patron, nor to the creator. It belongs to the cardholder.
The funds are removed from the creator’s balance. If there are not enough funds in the account, there will be a negative balance. Patreon does not reimburse based on fraud. Your account will zero out from future pledges and then return to normal.
More payments info in this help article.