I recently had a SaaS client cancel their sub-account subscription - this all worked fine and rendered their account inaccessible. However, what neither of us realised was that they would continue to be billed for WhatsApp and other add-ons they had purchased.

Since they had cancelled their sub-account, they could no longer log in to cancel their add-ons without restarting their subscription. Instead, I had to cancel everything on their behalf from my agency level.

It would be intuitive that if someone cancels their sub-account subscription, it cuts off all other add-on payments.