The flowers of coum are dumpy and have no auricles at the base. The flowers of hederifolium are more elongated and have auricles. The leaves are also different, coum has rounded leaves and hederifolium more pointed. If the plants you bought are in flower now, then it is very likely they are coum as hederifolium flowers from late summer to autumn. See pictures below for more detail,
Cyclamen coum flower
Cyclamen coum leaves showing a typical shape and pattern
Cyclamen hederifolium flower
Cyclamen hederifolium leaves showing variation within the species