Loud Engine Noise problems of the 2010 Toyota Camry

Sept. 16, 2013,the car made a loud noise and I pulled the car over to the shoulder of the road turned the car off to inspect the vehicle, I found nothing wrong, I contacted a wrecker and the closest Toyota dealership to have the car delivered for repairs. Sept. 17,I called them to find out what they found out about my car; I was informed by the service advisor that there is a hole in your block. I asked how could a car with only 56k mi. Throw a rod. He said they didn't know yet and would get back with me. Sept. 19, I provided the dealership with all of my service records. They contacted Toyota and called on sept. 20 they were going to remove the engine to look for the failure. They stated one of two things were the cause; the car was driven into a deep-water puddle allowing water intrusion into the engine or a component failure. I stated it wasn't even raining he day of the incident, his reply was then you have nothing to worry about. Sept. 23 they called to inform me the engine was removed, photos were taken and sent to Toyota for review. Toyota's stance was they were not going to replace the engine under warranty. Toyota claims that at sometime I allowed the oil level to get low, causing the engine to over heat and which lead to this failure. I stated that was utterly false, I routinely check the oil level in that car, it never requires top off oil in between oil changes. He apologized and said that is what Toyota is saying. I researched and found Toyota has experienced similar engine failures and they tend to push back honoring warranty claims. It is suspicious they did not remove the valve covers to check for probable causes in the head area since that has been the cause of these type engine failures. At this point, I have been advised to file this complaint with NHTSA; complaints with Toyota customer relations andthe owner of the dealership have also been filed.