Multiple Non Renewable Subscription

Sorry but I am bit confuse on implementing non renewable subscriptions.

Basic concept of app is user can post item to sell within the app. For each item to post he has to pay $.99. This item will remains there for 20 days.

As per apple documentation this kind of In App Purchase should be non renewable subscription with expiration logic to be implemented on Server side. I am done with everything like creating non-renewable IAP and integrating with app. Server maintains the expiration for each item.

Now my query is since user can post as many item he wants, how should the IAP ids should be maintain.

User Case #1: - User A posted one item after he pay $.99 for that. So far so good. - When he try to post next item, he is shown with the message "You have already purchase this, tap to renew or extend it" instead it should be something "Do you want to buy one xxx for $0.99" Am I missing something here?

Use Case #2: Now say item is expired (after 20 days), For renewing shall I use the same IAP id (Product ID in IAP) to renew? or I need to create different IAP id?

Please guide me on this so that Apple shall not reject the app.

Thanks in advance!!

OK I used following:

• non renewable subscription with expiration logic implemented on Server side.
• Same Product ID works for me for Buying for first time and renewing after 20 days expiration.

And application got approved!