After German employment rights (I am not a lawyer, so no guarantee) you signed an employment contract, they need to pay you. First when you receive a written notice you are out, currently you should be a member of the company from the date which is written down on the contract, which you signed.
Germany is really employee-friendly I really would contact an attorney.
I can't imagine that you don't get any compensation. Germany has good rights for employees. I would contact an attorney for employment law. Maybe you can get something. I mean you are in a very unpleasant situation.
Been there since many years.