What a funny company and I would say YYZ/Toronto Pearson Canada location is by far the worst location I've dealt with.

Background:
Had a rental back in November, 2020 and the return agent noted a pre-existing tiny rock chip on the bottom of passenger side windshield.
I told the guy it was pre-existing damage but it's way too small so I didn't mark it on the sheet. I took a video of the rock chip and other scratches before picking up but they didn't want to see it.
Talked with manager and was told that I might be responsible for it but they need to report it first. Manager didn't want to see my video either.
Don't want to waste time and argue, signed incident report, opened case immediately with AMEX and left.

No response from Hertz:
Waited until mid-December, 2020 but no response. I called this location multiple times and was told there was no charges on the phone. They refused to email me something as proof.
My contract was closed without further charges in December, 2020 but I want to make sure everything is all good.
I then called PC line and explained that I prefer to have an email reply saying that I'm not responsible for the charge. After 5,6 follow ups, finally received an Email indicating that there is no charge associated with the windshield damage.
Forwarded the email to AMEX as well and AMEX closed my case.
Well I guess that should be the end of story.

After 5 months:
Today, I just received a ridiculous email from their Canadian claim department and asked me to pay more than $500 CAD for a Nissan Kicks windshield.
Called this person in charge and she simply hung me up after introducing myself.
Forwarded email to this person and just waiting to see what would happen.

Update:
Received an email reply after 3 hrs and simply told me that the charged was dropped. No apology or further explanation.
It turns out that Hertz never contacted me and simply sent this mess to collection when they clearly said no charges last year.
I'm glad that I asked them for an email proof last year.
Upon further checking my mailbox today, a collection company on behalf of Hertz mailed me last week and asked me to pay the outstanding debt.

Things to learn from this joke:
1, Always mark all damages on the inspection sheet before leaving, no matter how small it is. I used to rent more than 30 times per year at pearson airport so I normally won't mark tiny damages. Now I guess they try to make profit of everything and no one cares about customer's loyalty/status.
2, Make sure to take videos/photos of both interior/exterior of the car including VIN number/plates/initial mileage/background etc.
3, If Hertz says something about dropping a charge sort of things, make sure there will be proof to support it. Record the call or ask them to send email as proof