I paid to exchange Sol Melia options for MAS points and had a confirmed reservation for friends at Gran Melia Cozumel. Upon arrival, they were told there was no availability and no record of reservations. After presenting confirmation e-mails, speaking with Sol Melia management and hotel staff, my friends were forced to find other accomodations in the area as there was nothing anyone could do to help, EVEN with confirmed reservations!
Sol Melia did not honor the reservation because it had been made through their loyalty program with MAS. What a horrendous experience!