Encore Marketing Intl i disputed Monthly charges to credit card and they sent a letter ststing I need to call to find out if I'm eligible refu lanham, Maryland

I requested a refund for monthly charges appearing on my credit card. I received a letter requiring me to call to request a refund. this is a common internet scam, you click on a free shipping or similar offer. you don't get free shipping or a refund for the shipping charge- instead you get billed monthly for no apoarent reason. when you dispute the charge, they claim that you enrolled in a program, which is not specified. No materials are sent to you but they claim that you were sent an enrollment package (again, unspecified).

I was unable to call during their business hours, but cancelled my enrollment using their phone system. I don't know if this will end the insanity or if I'll have to call back during business hours.