Know if Ios subscription was canceled in Unity IAP

I am developing a game for IOS and Android and its have In App Purchase. I'm using product.hasReceipt to verify if the subscription is still active and that works well on Android, but in IOS its don't. What i am doing is: if product.hasReceipt is true, the user has the subscription and unlock the content, if its false dont unlock or lock the content. But on Ios, after the first buy its never more became false even if the subscription was cancelled days before. Sorry my poor English and I hope someone help me.