I've seen a lot of info stating that Atradius Collections Ltd are not licensed to collect debts. However, a little searching lead me here:
https://register.fca.org.uk/shpo_searchresultspage?search=atradius
This seems to suggest they do have some sort of license.
I think there are other reasons for questioning the legitimacy of Atradius' claims. For example I don't see how they could bring legal action to recover debts without a judgement to back it up. Plus Atradius won't be the ones to take you to court for infringement as only the copyright owner or exclusive license owner (Getty) can do this.
https://register.fca.org.uk/shpo_searchresultspage?search=atradius
This seems to suggest they do have some sort of license.
I think there are other reasons for questioning the legitimacy of Atradius' claims. For example I don't see how they could bring legal action to recover debts without a judgement to back it up. Plus Atradius won't be the ones to take you to court for infringement as only the copyright owner or exclusive license owner (Getty) can do this.