Why was I falsely accused of water damage on my macbook pro?

I'm an apple product fanatic and I love your products, I even changed my phone from samsung galaxy s3 to the iPhone 5s early just to experience my laptop better. But when suddenly it stopped working my heart dropped. But luckily I still had a warranty and I took it to the geniuses at apple. After visiting the store they accused my computer of water damage. I told them over and over that water damage on my laptop was impossible and there was no way that it could be true. But they kept denying me and told me that it had water damage and that was that. They told me they would fix it for $800+ dollars. The laptop was $1200 dollars so basically the price it costs the apple people to fix it is almost equivalent to the laptop itself. Seeing that it was unreasonable I left the store with a heavy heart. As I felt that it was pointless to pay $800 i decided that it would be better to just get a new laptop. But then I saw an ad in my neighborhood and saw that my local ubreakifix store could fix my computer so I went there and asked them to fix it. When they asked me what was wrong I told them that the apple store claims that it was water damage. So then they took a look at my computer and to their surprise the damage was not water damage but an internal heating error. This occurs when there is something faulty in the fan. While reviewing my warranty it clearly states that my warranty doesn't cover water damage and physical damage. And internal heating damage isn't something I can control nor did I do it myself and since there was no water damage nor physical damage I have no idea why apple would not fix my computer. Clearly they accused me of water damage when there was none. So shouldn't my apple warranty cover the damages? Anyways I got a call from UbreakIfix saying that they tried fixing everything but it just won't work. They said something about the logic board being damaged because of the internal heat? I have no idea what is occurring to my laptop, but please apple find the kindness of your heart and please fix my computer. Please apple you need to help me I'm being falsely accused of water damage when there was none.If you don't believe me I am willing to send the computer or even take pictures of the inside to prove that there is no water damage. Please I am extremely desperate and I need your help.