They do not tell you but parking companies are just contractors - like the toilet cleaners or people that do repairs. But they have delusions which you need to point out to them.
The key delusion is they fail to remember they work for their clients and not the other way around. If you need a ticket cancelled the simplest, cheapest and easiest way to do it is to get whoever hired them to cancel. Called the Principal, the Principal can tell the parking company to stop and cancel it - at every stage.
Here are some of the larger clients with some suggestions on how to tackle them.