Dear @Emmytender,
I don’t think a lawyer should be necessary at this point. You could for now seek assistance from a free migrant counselling service (if you let us know what part of Germany you are in we can let you know where to find one) who can advocate on your behalf with the Ausländerbehörde.
One option would be to write them and describe in detail the situation: how long you’ve been waiting, the lack of communication on their part and any difficulties the lack of the physical card is causing you. I would set a deadline (two weeks) and state an intention to potentially file a legal action if the card is not issued by then.
The legal action is called a ‘Untätigkeitsklage. It’s possible to do when an administrative office (for example the Ausländerbehörde) does not act on a matter within three months. However, in your case it sounds as though they have granted you a settlement permit already, you just don’t have the actual card. I would therefore advise the action as described above (letter, description, deadline) before considering legal action.
Best,
Éanna