I'm not aware of any credit card limit around here, and apparently my neighbor isn't either. And lately I haven't heard of any other stations being "out of gas".
Most likely there is some hoarding going on somewhere. Back when they had the do not drive over 55 law, my husband's uncle worked as a Fire Chief in Phoenix AZ. He had to go around to inspect the large holding tanks. Even in the gas stations that were closed saying that they were out of gas, the tanks were always full.