Kernrechtsfrage
Whether the Federal Supreme Court should enter into the complaint despite non-payment of the advance costs.
Extrahierter Entscheid
The complaint is not entered into because the advance costs were not paid within the extended deadline.
Extrahierte Begründung
The payment order and the subsequent grace-period order were deemed served even though the mail was returned; it was the appellant's duty to notify the court of an address change. Since the advance payment was still not made, non-entry follows under Art. 108 BGG.