Debtor's petition to challenge execution proceedings filed against the enforcement of an arbitral award. Motion grounded on the non-existence of the arbitral award, not on its nullity. Inapplicability of the 90-day extinctive period. Non-existence of the arbitral award recognized due to the absence of valid submission of the parties to an arbitral tribunal. Condemnation of the judgment creditor to pay damages for malicious use of process: