If it's not fuses or seat relay then WHAT!!
It's a 2002 C320 wagon, help!!
It's a 2002 C320 wagon, help!! 
Ok, since no one wants to answer him (justifiably), I will.
The button on the seats controll everything EXCEPT the moving from front to back. This is manual.
Sitting in the drivers seat, look under your right leg below the seat next to the senter console. There is a lever there. Just like other cars that you have to manually move. Same goes with the passenger seat.
(I can't believe i'm typing this.)
Edit: In my defense, when I first got my C230, i thought it would have a button for that and not a manual knob, but i learned that quickly (within a few seconds).



