I had the same issue with mine, and today I took it to my service agent who had a look and said that it needed a software upgrade, which he did, and now the seat memory is supposed to be working, so I'll need to set it again and save the settings. I did notice since doing the software update, the passenger mirror now dips down, they also did one or two other bits and only charged my a very reasonable £60.
Knowing that it was a replacement car for my old one, which they looked after from new, they did give my new to me one a good check over and the verdict was that although it has done high mileage, it does not look like it, and they say that I selected a fantastic and well sorted and cared for car, which is good to know as I was a little worried about its mileage.