Seems like Tesla has always had problems with keeping track of free vs. pay-as-you-go Supercharging billing. I was never eligible for any free Supercharging. Didn't get it when I bought the car; haven't had anybody use my referral code; not living in any area graced by Tesla for getting free juice due to some act of Mother Nature. But, there's five times a charge session shows up in my History as being billed at $0.00 (at just over a year of ownership), at a location that had billed me both before and after those freebies. And there's half-a-dozen times I was at both the Glendale, CA and Kettleman City, CA Superchargers that don't show up in my History at all AND they were never billed to my credit card.
I've expanded one of these sessions to show that I didn't have any credit on my account, that I indeed sucked on some juice, but wasn't billed.
"The first rule about getting free Supercharging when you're not supposed to is: you don't talk about getting free Supercharging when you're not supposed to."