Didja have to swipe your card more than once because the pump flipped out when you passed $400?
Forget $400. We were filling up at a station about a year ago that had the pumps stop automatically at $75. When our Jeep's tank was near empty and required about $85 worth of gas to fill it up completely. The pump stopped when it hit the $75 mark, so Hubby swiped the card again. At which point the pump told him to see the attendant, because for some reason, it wouldn't take our card a second time. Hubby went to talk to the attendant, who said he had no clue how to get the pumps to take our card a second time, so we ended up leaving with a not-quite-full tank. Not much of a problem, except for the hassle with figuring out the MPG for that fill-up.
And around the same time, we had a few other times where we were almost on fumes when we had to fill up, and every other station we went to during the two months around the above incident either set their cut-off at $100 or higher (since it didn't cut us off at an even price) or had no issue with us swiping our card twice when we were cut off before the tank was full.