Why a 2008 XPS m1530 needs hardware support two times/year?

I'm very disappointed with quality of replaced parts. First touchpad (it stucks very often), then Graphics Card (temperature too high shut off the notebook - the first and second time - damaged video output the last time), Memory (too high temperature - 90°), Keyboard (space key stucks sometimes) and eventually the battery need replacement after two years and only so few use! (For much of the time i use AC).

I'm a teacher and ICT developer (and blogger), i don't suggest anymore Dell. I'm sorry, the next laptop will not be Dell.

PS. Sorry if i'm venting my feelings on this forum, but i think that phone support ignore the whole problem and continue to replacing low-quality parts that give me a lot of problem few months later.