@RH77 - I missed that, apologies for the essay
Yep, those companies also have to persue people to get their money and sometimes they (allegedly) put through some "test" cases with known "victims" who surrender so they can claim they have succeeded, but in reality they rely on people being scared of the official looking paperwork to get the money paid. If they send 300 invoices and 5-10 pay up they've made a profit.
If you did break any laws whilst here the hire company would have got the tickets, and if you from overseas sometimes they can't be bothered with the hassle.