I told a company (Delaware Swim and Fitness) not to charge my credit card, but send bills to me. I called my credit card and told them not to accept charges. It turns out this does not work unless the payments are set up as a "reoccurring charge" with the credit card company. CC will keep accepting charges. The only way to get a company to stop using your charge number is to report the card as lost or stolen, then cancel the CC account. Do not get a replacement number, the CC company will just forward the Fitness Center charges to it, leaving you to dispute why you are being charged for 15 months of membership when you canceled at the required 12 months of payments.