Objects rotate but remain on the original axis...

I'm trying to rotate a capsule with A and D and then move it forward and back with W and S ... Simple stuff... For some reason my capsule remains on the set Z and X axis even though it's visibly turning in the edit window, and I can see the surface of it rotating in the Game window too. Why is it not moving down it's new heading?? using UnityEngine; using System.Collections;

 public class PlayerMovementDon: MonoBehaviour {
 
     public int topSpeed = 5;
     public int acceleration =150;
     public bool active = false;
     // Use this for initialization
     void Start () {
     }
     // Update is called once per frame
     void Update () {
         if (active) {
             // JUMP
             if (Input.GetKeyDown (KeyCode.Space)) {
                 rigidbody.AddForce (Vector3.up * 1500);
             }
             // FORWARD
             if (Input.GetKey (KeyCode.W) && rigidbody.velocity.z <= topSpeed) {
                 rigidbody.AddForce (0, 0, acceleration);
             }
             // BACKWARD
             if (Input.GetKey (KeyCode.S) && rigidbody.velocity.z >= -topSpeed) {
                 rigidbody.AddForce (0, 0, -acceleration);
             }
             // TURN LEFT
             if (Input.GetKey (KeyCode.A)) {
                 transform.Rotate(0,5,0);
             }
             // TURN RIGHT
             if (Input.GetKey (KeyCode.D)) {
                 transform.Rotate(0,-5,0);            }
         }
     }
 }