Engine Clicking And Tapping Noises problems of the 2006 Mazda MAZDA3

I bought the car new from tracy Mazda in June of 2006. In April of 2008 I started hearing a slight ticking noise coming from the engine. This was shortly after the last oil change which was done by speedee oil changers. The mileage was 25,675, 4/18/08, when speedee changed the oil and it was 26,402, 4/25/08,when I took the car into tracy Mazda so they could check on the ticking noise. The service department finally got back to me several days later and said it sounds like a rod knock from cyl #1. They asked for the maintenance records which I then provided, except for one oil change which I had performed myself ( minus the filter which required a special tool). On 5/13/08 tracy Mazda's service department called and informed me they would not fix the vehicle under the warranty. It was going to cost me approximately $6,000. 00 to fix a car that didn't even have 30,000 miles on it. I declined to have them fix it right then and went and got the car. I had the first two oil changes performed at tracy Mazda's service department. The next was performed by speedee oil changers. After that I changed the oil myself. The fifth oil change was on 4/18/08, when I took it back to speed. The mileage between the two speed changes was 14,458. I performed one oil change between the two documented which would make it approximately 7,200 miles between the two. This is a little more than what is suggested between oil changes but not enough to warrant Mazda declining warranty repair. I plan on taking this up with Mazda's upper management in hopes they might make this right.