ORA-06550: line 1, column 7: PLS-00306: wrong number or types of arguments

I have problem with calling store procedure on Oracle 11g server.

stored procedure

PROCEDURE get_rit_by_user_id(KDC_KEY      IN VARCHAR2,
                             p_id_utente IN NUMBER,
                             p_cur_out   OUT type_cursor) IS
  BEGIN
    ...
    ...
    ...
  END

c# code

OracleCommand cmd = new OracleCommand();
cmd.Connection = oracleConnection;
cmd.CommandText = userIdEsercizio + packageName + "GET_RIT_BY_USER_ID";
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add("KDC_KEY", OracleDbType.Varchar2, kdcKey, ParameterDirection.Input);
cmd.Parameters.Add("P_ID_UTENTE", OracleDbType.Int32, user_id, ParameterDirection.Input);
cmd.Parameters.Add("P_CUR_OUT", OracleDbType.RefCursor, ParameterDirection.Output);

OracleDataReader reader = cmd.ExecuteReader();

cmd.ExecuteReader() throws this exception:

ORA-06550: line 1, column 7: PLS-00306: wrong number or types of arguments in call to 'GET_RIT_BY_USER_ID' ORA-06550: line 1, column 7: PL/SQL: Statement ignored

What is wrong with the above code that it gets a wrong number of types of arguments error?