Glad it got sorted out! Unless your trans is different than mine, that's not what the A and M are for. Sport mode is activated when you shift down out of drive into 3rd. The dash will show "S3" instead of "ED". Try it, you'll like it. Also very useful for driving in the mountains (engine braking).

The A and M are for auto and manual. It's normally in A. If you change it to M, then it forces the transmission into a manual shift mode and locks it into the gear selected with the shifter. This is good for winter driving when you want to avoided wheel spin at stoplights (put it in M and 2nd gear), but little else from my experience. I suppose you could put it in M and shift through the gears yourself, but it's not like shifting an MG!