Questione giuridica chiave
Whether the complaint is admissible despite non-payment of the court cost advance within the fixed deadline.
Decisione estratta
The complaint is inadmissible because the appellants did not pay the required advance nor prove timely payment within the non-extendable deadline.
Motivazione estratta
After proper warning under Art. 62(3) BGG, failure to pay the advance or submit the required debit confirmation triggers non-entry under Art. 108(1)(a) BGG.