Booking.com complaint: Lack of information

I think that Booking MUST verify that descriptions of the apartments are complete and accurate.
In my holiday in Lefkada (Greece), I found in the booked apartment something very unpleasant and I think that Booking is responsible of what happened. In the picture attached, there is the proof of what I am talking about. It is simply intolerable that during my holiday I had to follow the rule written in the bathroom. Please, imagine what unpleasant is that request for 9 days of holiday. I know that in some place in the world there are similar problems, but this is the first time that the toilet paper cannot be throw in the toilet.
I MUST know it BEFORE booking the apartment, and not when I was already there! If I had known it, I would have chosen another apartment, this is 100% sure. Note that, before my review just published, the apartment had a 1010 valuation that means “Exceptional”!!! How this is possible? Please, go there, stay for a week or so, use the bathroom and tell me how you can evaluate “Exceptional” this house. You can say……good, very good, but 1010 is out of question.
Clients must know this issue of the apartment, maybe for someone it is not a big problem, but the client MUST know it before taking an airplane to go there. It must be a client’s choice.