Please, enough of the victim bashing. It is obvious that had the OP not relied on the website and believed there was a heated pool the OP would have made other vacation plans. The vacation was very expensive and lacking in a promised amenity that was important to the OP. While pool temp would not be important to me, it is understandable that it was important to the OP and could be important to future guest like him who would make a different decision if they were not erroneously made to believe there was a heated, not semi-heated, pool.
This is not a roadside FI a family stays at for a night because it is near the Bar Mitzvah location or down the road from the state prison where they are going to visit a relative or near the fairgrounds; this is an expensive destination resort. There are different expectations and standards between the two. What one would expect at an FI pool is irrelevant except my hunch is most FIs would have probably raised the pool temp while the OP's family used the pool.
The OP complained while there, after getting home and having gotten nowhere, eventually on FT. Sorry to the posters who demand he should have come here first, but some people work on a solution first before going public. That's not being deceitful or wrong.