Re: How do I get my old companion back?

Not sure if the German version is different but normally if you go to the contacts and companions window by pressing N it will pull up all your contacts including vette which should allow you to re summon her again.  You will get multiple companions as you level, some you will have to use temporarily story wise but the contacts window under the N key will allow you to switch it around.

Also at the top menu of your game screen, click the "Fist" looking Icon which normally is the 5th icon from the left also opens the window.