Questione giuridica chiave
Whether the cantonal court arbitrarily found that the appellants disputed only the amount, not the existence, of the fee claim.
Decisione estratta
The complaint failed: the cited documents did not show that the contestation concerned the existence of the fee claim, and even if it did, that would not affect the legal qualification of the agreement.
Motivazione estratta
Arbitrariness in evidence assessment exists only if a decisive piece of evidence is ignored or misconstrued. The three cited exhibits did not prove what the appellants alleged, and the alleged factual distinction had no bearing on the legal assessment.