title: How to verify a iTunes Store receipt for in-app purchase
body: <p>First of all, I am not talking about calling <a href="https://buy.itunes.apple.com/verifyReceipt/">https://buy.itunes.apple.com/verifyReceipt/</a>, instead, what I am asking is how to verify an iTuneStore receipt from one of our users.</p>
  
  <p>We have in-app purchase in our app, and we verify in-game receipts on our server before we grant the product. However, this particular user claimed that he got charged by iTunes store but did not get the purchased products, and sent us his receipt as a proof. </p>
  
  <p>So I am wondering if there is anyway we can verify such a receipt. There is "receipt no" and "order number" in the iTunes Store receipt, however, with in-game receipt verification we get transaction_id, and these numbers are quite different. Any idea?</p>
  
  <p>Thanks in advance.</p>