Two different surprises with the same background: the CircuitMess subscription boxes (STEM Box and Wacky Robots) are discontinued, and existing subscriptions were wound down. Here is what each surprise usually is.
A shipping email you did not expect. When the subscription model ended, the boxes still owed to each subscriber were consolidated: instead of arriving month by month, everything remaining on the subscription shipped together in one final delivery. A shipping notice long after your last box is almost certainly that final consolidated shipment, not a new order.
A charge you did not expect. Monthly and six-month plans renewed automatically at the end of each period until cancelled; the one-year plan did not renew. The terms are in Subscription Policy — Full Details. A charge close to the moment you cancelled may have gone through before the cancellation took effect. Cancelling stops all future renewals (How do I cancel my subscription?), and if a charged order has not yet been dispatched, the standard rules in Cancellation policy apply.
If neither explains what you see — including if you never had a subscription at all; someone else in your household may have — email [email protected] with the date and amount of the charge, or the shipping email itself, plus the email address your subscription was under — we will trace exactly what it is and explain the options.