[Katya]

This goes for any credit card transaction: You can contact your credit card company and have the charges disputed, usually within one month to 45 days they will have credited your account for the disputed amount. It is then up to the merchant to prove that they were indeed due the amount credited. Most merchants, particularly when they've been pushing through unwarranted reoccurring charges will simply back down.
I have a business, and have also had customers who "regret" their purchase, try to scam me out of the charge for services rendered. One credit card company told me the consumer has two years to dispute a charge.

[reformedliberal]

I had a credit card that I only used for an "automatic reorder" with a business supplier.

When I needed to cancel the supplier, I could not reach anyone at all for 3 weeks, which was long enough for an unwanted delivery to be sent. So, I canceled the credit card.

When I called Visa, they demanded to know why I was canceling and I explained the situation. The guy on the "customer service" line laughed and told me that no credit card number was ever really canceled and if a merchant had the number, they could continue to send merchandise and bill the account. I was stunned, told him to cancel the account, sent them the copies of my request to the supplier to cease shipment and enclosed a formal letter promising to sue Visa if any further orders were accepted and charged.

I received no more bills from that card, ever and this was over 4 years ago. It took another two weeks after canceling the card to finally receive an acknowledgment from the supplier that my account with them had finally been canceled.

Even if I use something on a regular basis, I no longer authorize automatic resupply.