They had sought a reduction in the fines and penalties handed down by the Court of Appeal.
The ruling of the Court of Cassation issued last Monday is conclusive and final.
According to the apex court, the defendants have to collectively pay the blood money of QR200,000 to each victim. The money has to be paid to the legal inheritors of the deceased.
One of the worst tragedies to hit Qatar, the mall fire left 19 dead, including 13 children, in May 2012. The other victims were four staff of the Gympanzee daycare and two firemen.
In October 2015, a Doha court of appeal had acquitted five persons, who were held responsible by a trial court for the deadly fire. However, the judge had ruled the company that owns the shopping centre was guilty of involuntary manslaughter.
The victims included two-year-old triplets from New Zealand. Children from France, Spain and Japan also perished as did staff from the Philippines and South Africa.
The appeal court judge had said Gympanzee was not a nursery and concluded that it was an entertainment centre.