The freedom of information act requires the government to disclose, to citizens, most documents within the public record.  Although the police department would not be required to draft transcripts, the recordings of the calls themselves would probably be subject to disclosure.  Moreover, if transcripts already exist, they would be subject to disclosure as well.  Your next step should be to put a request, in writing, requesting the materials pursuant to the freedom of information act.  If the police department then fails to respond or refuses you can appeal that decision to your local freedom of information commission.