I've heard of many hotels honoring "mistake rates", though they're usually very firm about honoring them only to the letter. (No changes to names, dates, etc.)
I don't have "mistake rate" experience with Wyndham, but my experience with them when a hotel refused to check me into a room (see the power outage thread) gives me little hope for you in this situation. In summary, Wyndham's corporate-level support was basically unhelpful -- they kept deferring to the property-level management, which was not doing the right thing.
In the US, I suspect that a state attorney general would be interested -- many states have retail pricing laws that would be implicated. I'm not sure if the local authorities at this location would care.