I posted about this last summer. One time it took 4 HUACA before I got my points back, although I wasn't told (and didn't need to know) it was actually a "loan" until they finished their "investigation" 1 month later.
Avoid cancelling stays on weekends and on the website. App is usually ok although maybe best to do it on the phone - anyone had any problems with points refund when getting an agent to cancel?