Stamps.com Stamps.com is a rip-off Los Angeles California

Over a year ago I signed up for Stamps.com and cancelled just before the trial period ended.  I send several emails to cancel and called their phone number and spoke with a representative.  Every so often I receive an email from Stamps.com telling me they attempted to charge my credit card for the monthly fee which they now claim to total $315.00 which is bogus since I cancelled before the trial period ended.  I have send them a number of emails telling them that I cancelled but they still try to charge a card I cancelled after they charged me the first time.  I told them way back when this started that I cancelled but they keep on trying to charge a cancelled card.  I am referring this to the Attorney General in my state as it's a con-game they are running.  Even when you cancel they still try to charge you for their lack of service.  One reason I cancelled was I didn't find their service useful.  They are high priced and the service isn't that great either.