I had the same thing happen to me they sent me a Try Me offer , the offer clearly stated if you do not like it , do nothing . Well I got the same "Nasty gram" you got. All I kept thinking was , now I 'll never subscribe. I got about 5 of those 'Nasty Gram's" and after each one called them and got the same appology ... and "oh it was an error, we will make sure it never happens again". Well I guess they must think we have all lost our memories and if we get one of those letters we will rush off to send them a check.
It is terrible what tactics some of the companies are resorting to these days.