I'm trying to understand why you canceled a non-refundable booking and didn't expect to be out the whole amount? That's the meaning of "non-refundable". If you hadn't canceled then you might have had some luck if the property had a price match guarantee or something, as mentioned above. Having canceled it, though you have removed any potential and now you've paid for a room that you no longer have.

I suppose you could try and call the hotel and plead your case, maybe there's a very slim chance they would reinstate the booking? Worst they can say is no. But I don't see where this is any sort of scam. Rates change. As another poster mentioned, my rule is never to go back and re-check prices after I've made a non-refundable booking. There's no good that come from it, just frustration.