I work here in London. It is a money making scheme and it is legal because it is offshored in the UK. Unfortunately people desperate enough to take out an unsecure loan of only about $200 are probably the people that don't listen to the terms and conditions given to them verbally; they need money fast and the t&C aren't really on the top agenda.
They make the money by ruling out interest and using the term 'processing fees' to rope in customers. This is probably worse than interest- every time you receive your wage, be it weekly / bi-wkly/semi-monthly and you haven't paid the original loan, you need to pay the processing fee. What can start out as a $200 can surmount to a huge sum.
It is legitimate, although entirely unreasonable, but if you agreed to the terms over the phone then you have noone else to blame- there will always be people out there making money under these kind of practices.