fragment 화면전환 질문이요!!

Question

구글링으로 독학 중인 완전 초보자입니다 ㅜㅜ 

구조는 프래그먼트 안에 리스트뷰가 있고 리스트뷰 아이템 클릭시 다른 프래그먼트로 전환 해줄려고 하는데요!!

화면 전환이 안되네요ㅜㅜ 간단히 프래그먼트 코드만 한번 올려 보겠습니다

public class FragmentMain extends Fragment {
    IconTextListAdapter adapter;
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        ListView listView;

        View view = inflater.inflate(R.layout.fragment_main, container, false);

        listView = (ListView) view.findViewById(R.id.listView);

        adapter = new IconTextListAdapter(getActivity());
        loadItem(adapter);
        listView.setAdapter(adapter);

                listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
                adapterView.getItemAtPosition(position);
                IconTextItem curItem = (IconTextItem) adapter.getItem(position);
                String[] curData = curItem.getmData();

                changeFragment(position);

                Toast.makeText(getActivity(), "Selected : " + position + curData[0], Toast.LENGTH_LONG).show();

            }
        });

        return view;
    }

    public void changeFragment(int position) {
        int pos = position;
        Fragment fragment;

        switch (pos) {
            default:

            case 0: {
                fragment = new FragmentTest();
                break;
            }
            case 1: {
                fragment = new SubPageFragment();
                break;
            }

        }
        FragmentManager fragmentManager = getFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

        if (fragment instanceof FragmentTest) {
            fragmentTransaction.replace(R.id.fragment_place, fragment);
            fragmentManager.popBackStackImmediate(null, fragmentManager.POP_BACK_STACK_INCLUSIVE);
        } else {
            fragmentTransaction.replace(R.id.fragment_place, fragment);
            fragmentTransaction.addToBackStack(null);
        }
        fragmentTransaction.commit();
    }

    public void loadItem(IconTextListAdapter adapter){

        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));
        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));
        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));
        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));
        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));
        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));
        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));
        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));
        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));
        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));
        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));
        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));
        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));
        adapter.addItem(new IconTextItem(R.drawable.sin, "신", "", ""));

    }
}