Key legal question
Whether the complaint could be entered into after the court advance was not paid within the final deadline.
Extracted holding
No. Because the appellants neither paid the advance in time nor provided the required proof of timely payment, the complaint could not be heard.
Extracted reasoning
After a warning under Art. 62(3) BGG and a non-extendable grace period, failure to comply triggered non-entry under Art. 108(1)(a) BGG.