SQL query to pull out non-paying subscribers

[nogi]

I have various subscriptions on my site. The main one is called Premium, users that take this sub move from Regular to Premium user group and back when the sub expires. However, with the recent change of site ownership and paypal addresses, subs that are autorenewing/cancelling via PayPal aren't updating back on VB and the users are not reverting back to regular.

I've been able to proactively manage upcoming renewals by using the following query:
Membership Due Dates

SELECT user.username,user.email,subscriptionlog.expiry,subscriptionlog.status
FROM subscriptionlog AS subscriptionlog
LEFT JOIN user AS user ON (user.userid = subscriptionlog.userid)

But, how can I pull a list of users that are still in the Premium group but without any current subscription?