I loaded a load today with BVB Freight who sent me a rate con which stated 41,000 lbs. I weighed in at 31,560 empty and grossed out at 82,460. Since the load was only going 140 miles the broker (BVB Freight) from Issaquah, WA wanted me to haul this load illegally and when I told them that I wouldn't they told me they would send another truck in to get it. I asked them for a TONU and they hung the phone up on me and blocked my phone. I have a signed rate con, weight ticket with in and out times, date and inbound and outbound weights. Their MC# is 1164350 and USDOT# is 3514432. Their phone number is 425-459-1969. Avoid this broker if you should ever run across them.
In my opinion, if the weight of the load was more than agreed upon, the carrier is entitled to ask for more money. Maybe not $500, but still entitled to some compensation. As people stated before, it's added fuel consumption and wear on the truck. You should be compensated for that.