As an Avast user who hasn't used the Avast SecureLine VPN product I'm not aware of how the subscription structure works. More so when the purchase was via Google Play and how you would be able to link it to a windows device and not Android only.
However, looking at your image, I don't believe it is very clear as it is referring to what devices your subscription has been used with in the 'last 30 days.' There is nothing to identify exactly what those devices were.
You could try the following for clarification.
Sales change order details wrong email address given, etc. - Submit a support ticket
https://support.avast.com/en-ww/contact/sales in your case select the Billing, payment,
or license issues option - and then the I have a different billing or license issue and click Next and follow.
Give as much information as you can for them to identify, that said because this is for google play, I don't know how this would be referenced.