"Do NOT use them for excursions"

Do NOT use them for excursions! We used them in Punta Cana and was very disappointed. They refuse to refund our money. It was supposed to be a fun party boat. Their so called "supplies" denied anything wrong basically calling us lairs. They were 30 minutes late picking us up, an hour late dropping us back off, we didn't get what we were promised and the service was terrible. So many things were wrong with this excursion we would need a full page to explain. We basically took a boring boat ride the entire time.

"Avoid - left us stranded at an airport"

Booked an airport transfer online from Santo Domingo airport in Dominican Republic. Flight arrived on time - no sign of driver in arrivals hall. After searching around and waiting, gave up and got a in a dodgy beaten-up taxi instead, which was exactly what we were trying to avoid. Amstar refused to refund stating the driver was there, and that we has not shown up. If the driver was there, he was very well hidden!