inexistent warranty from Apple

I bought a Macbook pro 4 months ago and for a key problem they asked me to pay £1140 because was triggered the water sensor and when I asked to give me back the computer they said now my computer wasn't more turning on force me to pay a huge amount of money for repair it. After 10 calls with senior stuff no one called me back and the Apple repair center sent me an invoice for the repair whit specs diferent from my laptop.

Is it this the Apple customer service? And why there's not a complain center? and why they can say the computer is not on warranty because the liquid sensor is triggered when my computer was working perfectly but the problem with a key and haven't any problem with water?