Cuban? HUMMMM. See if there is a FUMO shop in Santo Domingo. Look at hotel Lina's Cigar shop.
Also look in the cigar shop next to the metro Bus Station next to Winston Churchill.
I have not tried to buy Cubans in Santo Domingo. the ones made in la Romana are very good, very, very good. in La Romana the FUMO shop in La marina is a very good place to buy genuine Cubans.
HB