There is an error in the above code I posted. Correct bitmap creation line to
Bitmap bitmap = new Bitmap(control.Width, control.Height); // use control.width and height
Then the above code will try to stretch the listbox to print bounds...see if the size after this change is ok....
otherwise try dividing the width and height by half to increase the scale like:
Bitmap bitmap = new Bitmap(control.Width/2, control.Height/2);