warranty get out clause

The selector button on my 8900 curve tracker ball failed some time ago, and as my warranty was about to end I sent it in via my service provider for repair.
It was returned saying there was moisture damage, and therefore my warranty was void. Following a request they sent a photo of the damage which is a slight amount of corrosion nowhere near the tracker ball.
As all my functions are working apart from that, I talked to the repair centre to ask them to confirm in writting that the corrosion indicated was the cause of the tracker ball selector button not working. They refused to confirm this.

So it looks like they have found a small area of corrosion which does not affect the phone operation at all, and are using this to get out of their warranty responsabilities.

If my assumptions are correct (please prove me otherwise) WHAT A CON JOB!!!!!

Can anyone confirm if this damage would affect my tracker ball selector mechanism???

If there is corrosion on the actual PCB or some of the components, and your trackball stopped working, then that is the problem.

You don't seriously expect corroding circuits to work correctly do you?

And the fact the corrosion is nowhere near the sensors makes no difference whatsoever. You see those very small lines all over the PCB? You have no way of knowing what each of those is for. One problem on any of those anywhere on the board can cause any kind of problem.