Question

Q: In a fictional scenario, imagine that Juan, an artist, entered into a contract with a gallery to exhibit and sell his artwork. The contract stipulated that the gallery would take a 30% commission on any sales made. Juan's artwork became very popular and several pieces were sold. However, the gallery failed to provide a detailed accounting of the sales and failed to issue proper documentation for each transaction. Juan only received a lump sum payment and cannot determine if he was unjustly deprived of any proceeds.

Advise Juan regarding his legal recourse under the concepts of unjust enrichment as provided for under Articles 22-23 and 2142-2143 of the Civil Code. Discuss the elements that need to be established to claim unjust enrichment and the possible remedies available to Juan in this situation.