This is a well-known scam and the poor kids going door-to-door are often under coercion. Might be worth flagging to @SgtBiddle if these guys are working the area.
Some bad feeling on here for what to me sounds like basic logic. We are today inundated with ways to donate to charity, so door-to-door visits from people brandishing bank details forms are understandably less successful and less trustworthy than in years gone by. There’s no way to guarantee someone tipping up at your door is legitimate. And I’m roiling at the accusation that people who don’t want the interruption/awkwardness/potential aggression caused by turning away a D2D caller are “cold-hearted”. I choose my charities and donate when I can in ways I can control.
Just had an aggressive young man on the door step (9 PM Saturday!) , with the suitcase of brushes and cleaning materials. If an institution or gangmaster is putting them through this, I feel sorry and would investigate or write on their behalf. I have found it hard to find out exactly what’s going on, however, as when I have asked previously the question was avoided, and I was told I was wasting his time.