Is it even owned by Amazon? If not, complaining to Amazon would be a bit like complaining to them if UPS left a truck in a driveway. That, and if they don't own it, they don't really have the authority to tow a contractor's van.
If it has a gigantic Amazon logo on it and delivers Amazon orders I wouldn't care that is some subcontractor. The blame falls on amazon
This truck had no logos.
It’s a contractor’s. If it was a UPS branded truck they could reach out to UPS. In this case the only thing they seem to know is that the vehicle is in operation for Amazon. So they naturally must reach out to them. And Amazon should at the very least be able to tell which contractors they use in the area, or rather even which contractor delivered a specific package.