Customer has two licenses that are both for the same solution or product. One of the licenses are a 500 count and the other is a 1000 count for a total of 1500 total licenses, yet after applying the licenses, he only shows 500 licenses total installed.
The last license installed is the license that is used. So if you install the 1000 user license last, you will have 1000 licenses. If you install the 500 user license last, you will get a total of 500 user licenses to use.
You should go to the Licensing portal where you are instructed to download your licenses and there you will find a Workshop tab. There you will be able to surrender your licenses and get one large license to download.