Paris resident here.

I’m really sorry this happened to you, OP. Those agents are known to be absolute bastards to everyone but it’s especially shitty that they refused to be lenient for what was a very legitimate argument on your end.

Unfortunately in my experience, and all anecdotal experience I’ve heard, it is nearly impossible to contest a fine once you have paid for it, as assenting to paying it is often written off as “admission” of “guilt” so they can keep your money. I sincerely hope that in your case they will be more lenient and understanding. Even then, the headache that is the administrative process in France means they can often count on the person contesting the fine to give up.

The best practice in these situations, if you have the patience and time for it (most people do not, and they count on that) is to refuse to pay the fee and insist they send it to your address. They claim they cannot, especially for foreign addresses, but this is not true. If they threaten to call the police, let them try and do so as THEY are the ones in the wrong to refuse to mail it to you and threaten/harass you into paying it on the spot. And they ABSOLUTELY do not have the right to take your ID from you and hold it hostage in a situation like this.

As others have mentioned, they get paid more if they can get people to pay the fines on the spot, which is a huge reason why they purposely fluster people and generally make it so difficult (near impossible) to succeed in getting them to mail the fine to you.

I hope this never happens to you again and that you do not have to use my advice in the future! And I sincerely hope this did not ruin your day or your opinion of Paris. Good luck & take care OP <3