Appalling. Really... they should not only refund you the entire stay but somehow compensate you for your wasted time and disappointment. The GM's behavior is not only odd, but bordering criminal.
Is this a sign we should rely on trusted brands? I thought they would be an reliable option and the prices seem OK for the size of the property, but your stay was anything but OK... very amateurish and unprofessional. I don't even know how to explain the GM's fraudulent behavior, did they explain? Anything?
I fear that along with the staff involved, the property's location has to do with the problems. While O&O in the Caribbean isn't that bad, their beach villas also suffer service problems at triple the price tag.
Glad you named the property in the title for SEO reasons...
Buyer beware.