Chargebacks are handled on a case by case basis and depend on how many are received in what time period across how many users. In some cases chargeback fees may need to be applied to your account before you can withdraw funds. You'll always have someone you can talk to regarding chargeback fees, please do contact support if you need to discuss chargebacks (and of course any other funding issues!)
Any user issuing an unjustified chargeback instead of requesting a refund will be removed from the service indefinitely. Any creator involved in fraudulent activity (that is to say they receive justified chargebacks) will have withdrawal requests blocked temporarily until the issue is resolved. This is because we need to prevent our service from being used for money laundering. Any cases of money laundering will be reported to relevant authorities.