Of course I would complain about cockroaches. It's a health hazard. Comparing the temperature of a pool with an insect infestation in a restaurant is very silly.

To the OP, I understand you were upset. The best thing you could have done was left the property. If the pool was closed for some reason, I could see demanding something. The fact that it was 25C instead of 28 or 29C is not going to get you much. They'll give you some points and that will be that.