You have a false expectation of the Betreibungsamt.
They are there to process the paperwork according to their processes.
The Betreibungsamt does not check (or even care) whether the claim is legal or not.
If you correctly raise a Rechtvorschlag then they will process it.
Of course, they will not cancel a Betreibung just because you ask them to.
Imagine the chaos if they cancelled Betreibungen every time somebody asked them.
As was already posted, this is is a civil matter not a criminal so the police will not help you.
Here is a link in German language with a lot more detail.
Note; The debt collection and the loss certificates are listed in a register of the debt enforcement office. A debt collection can be seen in the register for third parties for up to five years.
Premature deletion of a debt enforcement order from the register can only be obtained by withdrawing the debt enforcement by the creditor or by a court ruling that cancels the debt collection or judges the claim to be null and void.
The debt collection is not deleted from the register if the debtor pays the claim.
It is therefore recommended that, before paying the claim, the debtor requests the creditor in writing to withdraw the debt collection and have it deleted from the debt collection register free of charge after the claim has been paid.
However, the creditor cannot be forced to do so.