User Profile

I am using Auto-renewable subscriptions on my app and I am using sandbox users to test it with and for the first time purchase of an auto-renewable product in the app, its working fine, and the product gets renewed for the 6 times successfully (auto-renewable subscriptions renew up to five times after the initial purchase for a test environment). It's failing for the next subscription-like if we do subscribe to a subscription that has got expired(after 6 times of successful renewal of that subscription), a react-native-iap (In-App-Purchase) library is returning an incorrect receipt that is the old successful subscription's transaction receipt. Maybe it's a cache issue, but I'm not sure how to clean the cache or something like that. Any suggestion or solution will be highly appreciated..Thanks.

How often may my server query https://buy.itunes.apple.com/verifyReceipt in order to verify the status of an auto-renewable subscription? Is there any pricing or quota for this? To ask this another way, does this "verify receipt" endpoint have a connection limit (either per minute, per hour, or per day) that my server must respect to access it? (I am not able to find any mention of query limits and pricing in https://developer.apple.com/library/mac/releasenotes/General/ValidateAppStoreReceipt/Chapters/ValidateRemotely.html)

I am using app store server to server notification to check subscriber's subscription status. I am unable to find the pricing for the server to server notification (if there is any). I looked through every documentation related to the server to server notification for apple but couldn't able to find any solution.