Got my X5 today! But... something's wrong from the very start

[autoque]

I finally got the X5 today and drove only about 5 miles.
Since this is my first luxury vehicle, I was really impressed with the handling, albeit little bit heavy. (X5 3.0si)

But... the joy was short-lived... When I received the vehicle, the fuel gauge indicated that I had about 3/8 of fuel remaining. So I decided to gas it up with premium fuel. When 42 liters or 11 gallons of gas went in, the nozzle clicked, and I thought it indicated that it was full. So I went back in and drove off. But I quickly saw and realized that the tank was only about 6/8 full. I thought there was something wrong with the nozzle at that particular gas station. So I visited another gas station right away. And after about 7 liters or 2 gallons of gas went in, it clicked again. And that's when I realized something was not right. A gas station attendant approached me and asked what was going on, and I briefly told him the situation. Then he tried again, only to click again after a few seconds. I was just watching and he tried again and again, click after click and succeeded in putting 9 liters or 2.5 gallons of more gas, making it total of 16 liters or 4.2 gallons of gas on the second gas station. And that made the fuel gauge reach the maximum level.

So I put in 58 liters, or 15.3 gallons of gas all in all.

I'm not sure if something is really wrong and don't know if I should take it to the dealer. There's no warning sign but still...

Anybody know what's happening to the vehicle? Should I take it in?

So much for BMW reliability... Otherwise the vehicle is perfect. Except that it always tries to give me the lowest gear possible at all times, like whenever I take the foot away from the accelerator pedal.