Nice to hear from you again.
You said that the responsible person for your case in Berlin wrote a mail to Reutlingen. That happened two days ago. Maybe you should give them a little time to figure out what happened and call them back by the end of this week.
Otherwise it might be a good idea to go to Willkommenszentrum Berlin. They offer counselling at the following times (at Potsdamer Straße 65, 10785 Berlin):
Monday, Tuesday and Thursday: 09.00-13.00 (doors open at 08:00)
Thursdays also 15.00 - 18.00 (doors open at 14:00)
They might be able to tell you how to proceed in such a situation. Definitely check it out before consulting a lawyer because that's going to be way more expensive.