TL;DR: What options does one have at (US) airports when they know the luggage weighing scales are inaccurate?
This has happened twice now. My bags always appear heavier when measured at the flight check in counters. The weighing scales at the airport show them heavier by at least 5 pounds.
One time at Atlanta airport, although I was surprised that my luggage was overweight, the lady behind the counter didn't bother about it, but the last time I flew out of Dallas on an AA-Qantas flight, the lady behind the counter asked me to pay 100 bucks for going over my limit because the scale at the airport showed 50.5 lbs while the permissible limit is 50 lbs. When I asked to be re-weighed I was asked to join the end of the queue for further assistance as I was holding up other passengers for my 'irrational behavior'. I just had to pay up as I would have missed my flight.
I still want to know what options does one have at (US) airports when they know the luggage weighing scales are inaccurate?