Mangu is considered the best disco in Playa Dorada right now. Also check out Hemingways at Playa Dorada Plaza, it is pretty good at times.
American Casino has 2 locations now. One at the Holiday Place complex and the other at the Occidental Playa Dorada, it is smaller but nice.
I understand how you would lose patience. Unfortunately they do not all do a good job of marketing themselves!