Yaris 2014 headlight issue

[YarisEP]

hi everyone, I'm having a problem with both headlights, at night when the temperature is lower and previously was raining (or a few days before was raining), both lights get foggy inside. My car dealer already change both lights, and four days after, the moisture issue came again.

I don't know what to do, since they refused to change both lights again. According to them, Toyota Japan answered: If the moisture is not extreme, they aren't demand to change them.

I need technical information to be able to fight against them or if there a recall or something (I already google the issue but without results)

Manufacture date: oct 2013
Yaris Sedan 2014

thanks

(excuse for my english)