Libgdx group issue

//I tried to post all the important class and method to make it easier for you to track the issue


        SpriteBatch batch;
    Texture circleImg;
    Color redCol;

    private float rotSpeed = 10;

    public static Vector2 screenCenter;

    OrthographicCamera camera;
    ShapeRenderer shape;

    private Stage stage;
    private Group group;

    Paddle centerPad, redPad, bluePad; //this are the group elements

public GameScreen(final RgbX gam) {
        this.game = gam;

        screenCenter = new Vector2(RgbX.WIDTH / 2, game.HEIGHT / 2);


        circleImg = new Texture(Gdx.files.internal("circle2.PNG"));
        //a method to define all the colors
        setColors();
        //this is where i set up my group
        createThePaddle();


        camera = new OrthographicCamera();
        camera.setToOrtho(false, game.WIDTH, game.HEIGHT);
        batch = new SpriteBatch();
        shape = new ShapeRenderer();
        Gdx.input.setInputProcessor(this);

    }
@Override
    public void render(float delta) {
        // TODO Auto-generated method stub
        Gdx.gl.glClearColor(0, 0.0f, 0.0f, 0);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

        //in this method i control the group with inputs
        groupUpdate();

        //drawing the group
        stage.act(Gdx.graphics.getDeltaTime());
        stage.draw();


        //attempts to get the rectangle
        for (Actor ac : group.getChildren()) {
            Vector2 pos = ac.stageToLocalCoordinates(new Vector2(0, 0));

            System.out.println(pos);
            //i have a method to return a rectangle but i can't use it
            Rectangle rect = new Rectangle(pos.x, pos.y, ac.getWidth(),
                    ac.getHeight());

            shape.setProjectionMatrix(stage.getCamera().combined);
            shape.begin(ShapeType.Line);
            shape.rect(rect.x, rect.y, rect.width, rect.height);
            shape.end();

        }


    }
//the group setup method :
private void createThePaddle() {
        // Create a stage
        stage = new Stage(new StretchViewport(game.WIDTH, game.HEIGHT));

        // Create a group and add it to the stage.
        group = new Group();
        stage.addActor(group);

        // Create images and add them to the group.
        Sprite sprite = new Sprite(circleImg);
        Image image = new Image(circleImg);
        //this is what the paddle class take (i'll post it below)
        redPad = new Paddle(redCol, "red", sprite, image, new Vector2(0, 0), 1f);
        bluePad = new Paddle(blueCol, "blue", sprite, image, new Vector2(0, 0),
                1f);
        //adding the actor (i don't know why i can't add the object itself)
        group.addActor(redPad.getImage());
        group.addActor(bluePad.getImage());
        //setting the position relative to the stage
        redPad.getImage().setPosition(10, 0);
        bluePad.setPosition(new Vector2(20, 0));
        //setting the group position in the middle of the screen
        group.setPosition(RgbX.WIDTH / 2, game.HEIGHT / 2 );

        group.setScale(.5f);

    }
//this method is to update the group
private void groupUpdate() {
        if (Gdx.input.isKeyPressed(Keys.LEFT)) {
            group.rotateBy(rotSpeed);
            // group.setX(group.getX() + 100 * Gdx.graphics.getDeltaTime());
        }
        if (Gdx.input.isKeyPressed(Keys.RIGHT)) {
            group.rotateBy(-rotSpeed);
            // group.setX(group.getX() - 100 * Gdx.graphics.getDeltaTime());
        }
    }

/***** The Paddle Class  ****/
package com.aladine.rgbx;

import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.g2d.Sprite;
import com.badlogic.gdx.math.Rectangle;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.scenes.scene2d.ui.Image;

public class Paddle {

    public Color color;
    public String type;
    public Image image;
    public Vector2 position;
    public Sprite sprite;
    public float scale;
    public Rectangle rectangle;

    public Paddle(Color color, String type, Sprite sprite,Image image, Vector2 position,
            float scale) {

        this.color = color;
        this.type = type;
        this.position = position;
        this.sprite = sprite;
        this.image = image ;
        sprite.setColor(color);
        image.setColor(color);
        sprite.setSize(sprite.getWidth() * scale, sprite.getHeight() * scale);
        sprite.setOriginCenter();
        setRect();

    }

    public void setRect() {
        Rectangle rect = new Rectangle();

        // change the rectangle size to match the sprite
        rect.width = sprite.getWidth();
        rect.height = sprite.getHeight();
        rect.x = sprite.getX();
        rect.y = sprite.getY();

        this.rectangle = rect;
    }

    public void updateRect() {
        this.rectangle.x = position.x;
        this.rectangle.y = position.y;
    }

    public Color getColor() {
        return color;
    }

    public void setColor(Color color) {
        this.color = color;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public Image getImage() {
        Image img = new Image(sprite.getTexture());
        img.setColor(sprite.getColor());
        return img;
    }

    public void setImage(Image image) {
        this.image = image;
    }

    public Vector2 getPosition() {
        return position;
    }

    public void setPosition(Vector2 position) {
        this.position = position;
    }

    public Sprite getSprite() {
        return sprite;
    }

    public void setSprite(Sprite sprite) {
        this.sprite = sprite;
    }

}