This has happened many times to me. More recently I’ve noticed that certain gas stations where I’ve had this happen have raised the limit. What’s really annoying is that if you hit the limit, and try to use the same credit card again, it’s automatically rejected! You have to use different cards to complete the fill-up.
I have hit the $75 limit on my AMEX card, but I have yet to have a second charge rejected. I guess it depends on where you go...