The memory seats are a bit counter intuitive to use - I needed to figure mine out as I used the spare key to unlock the car without realising the key was linked to a seat position, so my unstored driving position got completely buggered up
To store a seat position you have to hold down the button that doesn't look like one saying 'memory' then press a numbered button for over 1 second to store.
Once that's sorted you can then link your individual key to a seat programme by leaving the driver's door open, put the seat in its desired stored position, keep the recall button (whichever number you're using) pressed down and press and release the unlock button on the remote, then wait a couple of seconds before releasing the recall button on the seat control.