Now I always take a picture, and make sure I get a receipt from the gas station.

Same car rental, I did the Avis preferred thing where I just went to my vehicle and showed my ID at the exit.
I get an initial email saying the rental had started. We drive about 60 mile away, have lunch with family, and then go to a friends house.

I notice another email that says they are sorry, but they are cancelling my rental because they couldn't hold it for me any longer (e.g., they thought I had never picked up the car).

I call Avis and get passed around to various people, none of whom speak English as their first language. One time I got put on hold for forever until the call dropped. Another time I may have lost the call due to a poor cell signal.
I finally get someone again and explain the situation... I already have the car... you think I never picked up a car, can we please get this corrected.

The guy refuses to help me and tells me the only way to fix it would be to go to the airport rental counter. I ask to speak to supervisors. No one can/will help. I end up having to drive the 60 minutes back to the airport. I did get them to comp one day of rental... but they didn't even offer that up until I demanded some compensation for my time, gasoline for 120 miles of additional driving, etc.