Jigsaw Drag and Drop Game? Help!

I am trying to make an educational jigsaw with pieces of the skull being fit together, but I am having no luck with dragging and dropping the jigsaw pieces. I need to make it for a touchscreen, but just cannot seem to get anything to move.

Not sure if there's something I am missing, I have colliders of the jigsaw pieces, with the trigger event chosen, and when I used Debug.Log with OnMouseDown it registers the click, so unsure why it isn't moving the pieces.

Is there something else going wrong? Please help!

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class Draggable : MonoBehaviour {
 
     [SerializeField]
 
     private Transform bonePlace;
 
     private Vector2 initialPosition;
 
     private float deltaX, deltaY;
 
     public static bool locked;
 
     // Mark the bones initial position
     void Start () {
           initialPosition = transform.position;
     }
     
     
     private void Update () {
 
         // if screen is touched and the bone is not locked in place, the bone will move
 
         if (Input.touchCount > 0 && !locked)
 
         {
             Touch touch = Input.GetTouch(0);
             Vector2 touchPos = Camera.main.ScreenToWorldPoint(touch.position);
 
             switch (touch.phase)
             {
                 case TouchPhase.Began:
 
                     if (GetComponent<Collider2D>() == Physics2D.OverlapPoint(touchPos))
 
                     {
                     Debug.Log ("PickedUp");
                     deltaX = touchPos.x - transform.position.x;
                     deltaY = touchPos.y - transform.position.y;
 
                     }
 
                     break;
 
                     case TouchPhase.Moved:
 
                     if (GetComponent<Collider2D>() == Physics2D.OverlapPoint(touchPos))
                         transform.position = new Vector2(touchPos.x - deltaX, touchPos.y - deltaY);
 
                         break;
 
                     case TouchPhase.Ended:
                     // if the bone isn't in the right place, it will move back to inital position
                     if (Mathf.Abs(transform.position.x - bonePlace.position.x) <= 0.5f &&
                         Mathf.Abs(transform.position.y - bonePlace.position.y) <= 0.5f)
 
                         {
                             transform.position = new Vector2(bonePlace.position.x, bonePlace.position.y);
 
                 
                         }
 
                         else
                             
                             {
                                 transform.position = new Vector2 (initialPosition.x, initialPosition.y);
                             }
                             break;
                         
             }
 
         }
         
     }
 
 
 }