it can't rollover for 5 months, that's not how they work
as soon as you're late their collection team is on it, interest only accrues for 60 days, they will probs then pass it onto a collection agency so the uberhigh interest will stop
The people who use this service are living pay day to pay day, hence when they come to repay the initial £100 loan they will then be £120 short that month, hence they then borrow £120 effectively rolling over the loan.