A user registered to a certain plan I defined, a free plan - lifetime subscription.
Now this user logs-in to the system and subscribes himself to the same program again.
The system allows him to do that, but I want to prevent him from doing this action
If a user already subscribed to a plan, I do not want him to be able to subscribe the plan while it is still active for him.
If he tries to do so, I want him to get a message that he is already registered for the plan (and redirected automatically to the relevant page of the plan as defined for registered users.
How can it be done? what definitions should I make for the system to act as I want.
Even partially will be good for me, as long as the user will not be able to subscribe to a plan that he is already registered to
