I want to add my experience here, hope it will help others.
I received on Sep 13, 2022 of two fines $3750 + $3750 (my wife), after spoke to Revenu Quebec agent named on the paper, I replied with non-guilty since it was the only way if you want to fight. To my surprise, the court was set up very quickly for Dec 5, 2022.
I went to court alone this Monday, the judge told me I could not represent my wife unless i'm a lawyer. When it's the time to negotiate with prosecutor, I told her I wanted to fight for both of us, and I didn't expect that I couldn't even represent for my wife. Right away she gave me an offer, if I feel guilty, she will remove my wife's file. That is already the best I could ask for! As many of the cases, the fines are against to everyone on the property list, no matter if they are involved in or not, sometimes even to the baby.
And after that, when I was facing the judge, I requested if the judge could remove some fees since (I lost my job, have two kids, but you could say any of those reasons), the judge agreed to remove the additional fees, so for my file, it will be the minimum $2500 plus administration fee, total about $3000. This part you have to ask from the judge, since the prosecutor told me before the judge is the only one to make the decision on that part.
I left the court with fines from $7500 down to about $3000, payable within 12 months. Hope it will help you to reduce part of your fines. Good luck!