when I had missed 90-day report, and thus technically on overstay, I pointed out my error to the passport officer when leaving BKK, and explained how that could happen, and asked his advice. He concluded: "no overstay".
Same tactic may work here.
if male officer blame the guilty in a joke, if female blame yourself, language problem.
When I did last renewal a few months back, I was advised that it would be wise to put a few Baht extra on the account because there had been cases where bank charges caused a low balance, and this office was refusing the extension.