The Sunwing Travel Company seems to be another shady operation.
They're based out of Canada, which is why you haven't heard of them if American.
Check out these reviews on Yelp for Sunwing:
https://www.yelp.com/biz/sunwing-vacations-etobicoke-2
It seems that Sunwing is a disorganized mess, and they entice people with seemingly cheap all-inclusive vacations. Then people end up having a horrible experience in just about every way possible.
Keep in mind these bad reviews are for other destinations -- not even the Punta Cana scam here!
Sunwing is no doubt very aware of the scam at the Riu, but they probably get the hotel very cheaply (likely BECAUSE of the scam), so they can make a lot of money on these "vacations", despite the low price.
That's a big problem in general when you let travel companies book your airlines, accommodations, etc. They often have super-discounted contracts with airlines, hotels, tour operators, and you get the bottom barrel shit of everything.
Or, as my Jewish grandfather used to say, "I'm not rich enough to afford a bargain."