You must have. You signed up for their trial membership to get free shipping at one of their member sites, didn't you? In order to qualify for your initial free shipping rebate, you had to complete a screen with your full name, address, password, AND DEBIT CARD NUMBER. It would not let you go to the next screen until you checked the box that said you had READ and AGREED to the terms of membership: that if you did not cancel within the 30-day trial period, your card would be charged the monthly membership fee. If I were you, I wouldn't be here making a complaint...I'd be going to their website, signing in using the email address and password that YOU GAVE THEM, and following their membership cancellation procedure immediately. Because as it stands now, you are a member of freeshipping.com and that amount will be charged to your debit card EVERY MONTH until you cancel.
The only other way that they could have done it is if you gave someone else your debit card number (or allowed it to be taken by being careless with it) and they used it in the manner described above without your knowledge.
(Btw, there is no such word as "permmishing"----do you not own a dictionary or know how to use spell-check? That's also what the red squiggly underlining means: it's to get your attention that the underlined word is misspelled, so you can fix it.)