Call your bank with the info in case the company tries to charge you again. They will do an investigation and can stop further transactions from this company, obviously based on your cancelation with them (you will need to provide the bank with the details and with your e-mail to the company requesting the cancelation).
Otherwise, you could get lost in the "oh, our computer already had the next shipment set and there wasn't enough time between your cancelation and that scheduled time to stop this next shipment, and now there's a 60-day wait for the return of your funds" and blah-de-blah.