No Registration Fine While Waiting For Trial On Same Thing

I was fined for not having valid registration tonight, I am currently awaiting a trial date for the EXACT SAME offense. I was under the impression that I couldn't be fined for the same thing twice. The officer said "until you sort it out I can fine you for whatever I want". Now the reason that I am going to trial is that there is another fine on my license that I have no information about and have been trying to determine where it came from. I didn't know about this fine so when I went to register this year it was an additional charge. I have been having trouble getting information about what that fine is in regards too, I explained this to the prosecutor at my early resolution meeting and he said that he would set a trial date to give me more time to figure out where this fine came from.

Obviously I am going to choose early resolution again but I am just wondering if I should file a complaint against the officer or if I am incorrect in assuming I couldn't be charged for an offense that I am awaiting trial for.

You are incorrect. You could be stopped every time you take the car on the road. Imagine if you were right and you were awaiting trial for having no insurance and so you could drive with no insurance for the best part of a year. That makes no sense.

Am I just supposed to blindly pay this fine that I have no idea where it came from then?

Yes you should just pay it if you want your registration fixed, and want to stop getting tickets.

Then you can track down what the fine was for and decide if it is something you were wrongly charged for and then you can pursue it and have it removed from your record and get reimbursed for it.

If the outstanding fines are prohibiting you from renewing your licence plate, it's likely that it's from a parking infraction, or red light camera.

Outstanding fines issued under the HTA result in a suspension of a drivers licence.

You need to go service Ontario and/or your local court to determine what the fine is.

Without a valid plate/permit, the officer doesn't even owe you the courtesy of letting you drive away after the infraction. He could force you to tow the vehicle from the roadside or contnue ticketing you if you chose to drive away.