Cannot update thru App Store after buying S3 update through L&L

After using S 2 for years I bought S 3 through the L&L website to get the upgrade discount. I had bought it through the App Store, assuming that the discount would be applied there. It was not, so I was refunded by Apple, and bought the upgrade through L&L.

Now there is an update for S 3 available through the App Store, but I get this error message:

Update Unavailable with This Apple ID

This update is not available for this Apple ID either because it was bought by a different user or the item was refunded or cancelled.

Apple tell me I have to purchase S 3 from them in order to get updates through the App Store.

They also tell me that L&L should have made the discount available through the App Store in the first place to avoid this problem.

So: How do I fix this problem?

You update through the L&L site. You can only update App store apps on the App store.

Okay - how is this done?

Under the “Scrivener” menu, choose “Check for Updates”. Also, in the Preferences, under General > Startup, if “Automatically check for updates” is ticked then Scrivener will automatically notify you when there is an update available.

All the best,
Keith