I read a few post in this forum and can now confirm that all these sites are fraudulent! You should NOT pay anything (even the original 4, 87$ they are SUPPOSED to charge only). I was charged close to 150$ in total on my credit card by now and I don't think I will ever be reimbursed.
You can send an email to email@example.com<firstname.lastname@example.org> and email@example.com to cancel your account but I have not yet got any confirmation of a refund of any sort :-(
But if someone can benefit of reading this before registering to any of these sites, it will be a good thing at least!