Facts
The appellant, [A. AG] , is pursuing [B.] (the debtor) before the Debt Collection and Bankruptcy Office of La Chaux-de-Fonds (debt collection no. xxxxxxxxxx). The debtor filed an objection to the payment order on 21 November 2018, contesting his non-return to better fortune within the meaning of art. 265a DEBA.
By decision of 25 February 2019 (ML.2018.1574), the Civil Court of Littoral and Val-de-Travers, ruling in summary proceedings (art. 251 let. d CPC), declared the objection admissible.
By submission of 27 March 2019, the appellant filed a subsidiary constitutional appeal with the Federal Supreme Court. She principally requests that the cantonal decision be annulled and reformed, such that the objection be declared inadmissible, and subsidiarily that the matter be remitted to the prior authority for a new decision. No observations were requested.
The appellant's main complaint concerns a violation of her right to be heard (art. 29 para. 2 Cst.). She reproaches the prior authority for not allowing her to submit observations on the debtor's response. According to her, the court merely invited her to take note of this response and to inform it whether she wished the proceedings to continue.
It appears from the file that, by letter of 4 December 2018, the cantonal judge gave the debtor a 10-day period to produce a detailed statement of his income, expenses and assets. The debtor responded on 3 and 4 January 2019. By letter of 8 January 2019, the court forwarded this response to the appellant, inviting her to comment within 10 days, failing which the proceedings would continue, with a decision in principle rendered without a preliminary hearing. The contested decision was issued on 25 February 2019. The appellant also received, as an annex to a letter of 21 January 2019, the creditor's submissions dated 16 and 19 January 2019.
Considerations
As to admissibility, the Federal Supreme Court notes that the decision was rendered in summary proceedings pursuant to art. 265a para. 1 DEBA. It is a final decision of a pecuniary nature in debt enforcement matters (arts. 90 and 72 para. 2 let. a FSCA), which is not subject to any cantonal appeal. As the appellant alleges a violation of her right to be heard, which could not be remedied in the action for a finding of non-return to better fortune (art. 265a para. 4 DEBA), the appeal is open under art. 75 para. 1 FSCA, this provision constituting a special rule derogating from the requirement of a higher court (art. 75 para. 2 FSCA). The amount in dispute does not reach 30,000 francs (art. 74 para. 1 let. b FSCA) and no exception applies (art. 74 para. 2 DEBA), so that only the subsidiary constitutional appeal is open (arts. 113 et seq. FSCA). Filed in time (art. 100 para. 1 FSCA), the appeal is admissible.
As to the reasoning, the appeal for violation of constitutional rights (art. 116 FSCA) requires precise and detailed argumentation (arts. 106 para. 2 and 117 FSCA), which the appellant does not provide.
On the merits, the right to be heard (art. 29 para. 2 Cst.) guarantees in particular the right to express oneself before an adverse decision is taken, to access the file and to comment on any argument presented to the court. The court must guarantee an effective right of reply: any position or new exhibit must be communicated to the parties, with a sufficient period between such communication and the decision. According to case law, a period of less than ten days is not sufficient, whereas a period exceeding twenty days permits an inference of waiver of the right…