Red and Black Syndrome by Daniel Dembrosky

Sensuous Lena is a twenty-eight-year-old who, initially, appears to get everything she wants—world travel and lodging at first class casino-hotels, clothes from the finest fashion houses, meals suited for a queen, pampered services of various sorts—all due to fantastic luck at the roulette wheel. Her extraordinary fortune arises from a deal with a demon—a deal made so Lena can win the enormous sums needed for the round-the-clock medical care which keeps her mother alive. But when she falters in keeping her end of the bizarre bargain, however, Lena faces paying the devastating consequences. She is compelled to overcome the same evil power that bestowed her fortune in the first place.