Felt ripped off

There's no doubt the diet works but I feel so conned when I joined rosemary Conley online I understood the offer of £9.99 as a debit card payment was a 1 off fee as debit card payments usually are I did not set up a direct debit so therefore thought that was it it was only 3 months later when I checked my bank statements I realised a £12.99 monthly fee had been taken. I have only known this before if a direct debit has been set up. I was so annoyed I rang up to query only to be told it's in the terms and conditions beware I think this is sneaky and must have caught out many others