CN lost my business forever when they charged me £35 to end a £25 VIN number only policy, I wished I'd just not told them and left it to lapse. When my Harley got backed into by a blind bitch in a Freelander, they did a good repair job, including replacing parts that were barely scratched, but charged the claim with more than the retail price of the crap Suzuki they hired it me for 3 months while they waited for parts. If I'd known they were going to do that, and that it was going to take a whole summer, I'd have insisted on the hire of another Harley, I'm sure I'd have been within my rights to.
Regarding helmets, when I raced bikes there was a specific clothing scrutineer who always checked the age of your helmet using the label inside. She made me buy a new one, but when I ended up in hospital after a big pile up at Aintree, and noticed someone else's tyre mark on my lid, I was glad she had. That was my last race, I decided to get out while I could still walk without a permanent limp, unlike several of my mates.