A few weeks ago, I availed of a 30% promo and booked a stay at the cheapest Radisson I could find near where I live. I did this so I could collect 50K Carlson points which is enough to redeem 5 nights in their lower category hotels or 1 night at any of their top tier properties worldwide which go for $500+.
The hotel I booked was this one in Carteret, New Jersey which despite the good reviews on TripAdvisor is in the middle of an industrial zone with plumes of smoke coming from nearby factories. Long story short, having driven past the hotel earlier in the day I decided to cancel but I forgot to do so by the 6pm deadline. I called at 7pm and I explained my plans had changed due to flight issues and assumed that was that.
This week a charge showed up on my credit card for $90 (bummer) but almost instantly 50K showed up in my Club Carlson account (hell yeah!) I am not going to fight the charge because I was just going to stay there as a mattress run to get the promo 50K bonus so I’m more than happy to pay $90 for 50K points which can be redeemed for a $500 top tier hotel in Europe / Asia. I don't know if calling to cancel gives you a better chance than a pure 'no show' - as always YMMV - UPDATE: After more research I realized the original cancellation was honoured and no charge was issued: I had booked another reservation online and did not cancel so was charged for the 'no show' i.e. 'no show counted for the bonus points and no need to call to cancel!