Good day fred, thanks for your question. I am glad to be able to provide assistance to you today. Kindly check and refer to the below and if you will still encounter an issue you can also reach out to the dedicated team for subscribers via the link below and they will help out with regards to this as well.
> Sign in to https://manage.visualstudio.com
> If you're an admin on more than one agreement, choose the desired agreement from the drop-down list.
> Select the Overview icon at the top left to display information about your subscriptions.
> Locate the entry for the subscriptions you wish to cancel, and select Change quantity. This takes you to the Visual Studio Marketplace where you can update your purchase quantity.
> Set the quantity to zero (0). Your subscriptions remain in place until their scheduled billing date, but don't renew when the billing date is reached.
https://my.visualstudio.com/GetHelp
Regards,
Paul R.