Android in app purchase-query inventory returns null after deleting and re-adding account

Question

I have implemented in app purchase to my application by following the google's documentation. Everything works fine as expected, I can purchase items and after deleting the application I can restore my managed purchases with this code there has been no problem so far.

IabHelper.QueryInventoryFinishedListener mGotInventoryListener 
= new IabHelper.QueryInventoryFinishedListener() {
public void onQueryInventoryFinished(IabResult result,
  Inventory inventory) {

  if (result.isFailure()) {
    // handle error here
  }
  else {
    // does the user have the premium upgrade?
    mIsPremium = inventory.hasPurchase(SKU_PREMIUM);        
    // update UI accordingly
  } 
}};

Here is the part I want to know about, if I remove and re-add my account that I made purchases and try to query my inventory it returns null, so I can't restore my purchases and when I try to buy it again it returns with message : You already own this item.

Also my app and in app products are currently published on alfa and I'm using same keystore(publish keystore) and same version code.

So am I missing something, any help is appreciated.