Oh, the dreaded "pump won't take my credit card, I'm 150 miles from home, and I don't have enough cash to buy enough gas to get home! (And I'm too exhausted to drive another 30 miles looking for a gas station!)" I did the exact same thing -- took my card inside, asked why the pump wouldn't take it. They didn't have a clue, offered to run it through inside the store. OK. While they did that, picked out my snack item and paid cash for it.
Got home, started the report. Humph. No place on this report for my gas purchase? Well, that's silly. Very strange. Don't recall EVER doing a MF gas station where gas purchase wasn't required and reimbursed...oops, wait a sec, this wasn't MF! Same gas station, different company, LOL!!! No gas purchase required!
Lucky, I guess, because if it had been, my report would have been invalidated, just as yours was.
Just remember...take a few deep breaths, count to ten, have a nice cuppa (or something stiffer!) and remind yourself: The only person who makes no mistakes is the person who is DOING NOTHING!