I'm thinking the best way to do this would be a notice advising them but there is no easy way to do this, so I think I've come up with a bit of a convoluted way of doing this.
So I've already got a Premium Members User Group. I was thinking of creating another user group called Previous Premium Members and creating a user promotion so that if someone is in the Premium Members User Group they are automatically promoted to Previous Premium Members group.
I then plan to set up a notice with the following conditions set:
User is a member of any of the selected user groups: Previous Premium Members
User is NOT a member of any of the selected user groups: Premium Members User Group
Will this work? and do you guys think this is the best way to go about it?