Protest, let the company, not the agent know you are unhappy. Many times, some small clerk makes decisions on their own, and if it is of benefit to the company, great, maybe a silver star or what ever. But when it is wrong, and they get their nose rubbed in it good, they back off rapidly.
Case in Point: Before I retired, I owned and operated my own 18 wheeler, running on average of 110K miles per year. I owned an older Nissan pickup, and had on occasion, put some hefty miles on it annually, but I have yet to learn how to drive two vehicles at same times, so mileage did not build fast on the Nissan. Used it to go purchase oil, filters, etc for the big rig, and often a month would go by without it being moved.
The company that carried coverage on my wife's auto, the Nissan, my home, and some other stuff, offered a special discount if annual mileage was 7,500 miles or below, and this pick up often did not get 500 miles per year, but still to keep tags on it, had to have insurance.
They would every so often send a form to fill in the odometer readings, I guess hoping to catch folks getting the discount while actually driving more miles than allowed. I always filled them out, returned them, however in a five month period, I received and sent back in 5 such forms. Some did not show any difference, others less than twenty per month, etc., but they kept coming. It finally pissed me off. This time I returned it and a letter to the president of the company, explaining my displeasure, as apparently some member of his organization seemed to think I was not telling the truth, and he or any one else was allowed to check the situation, but with one more of those forms implying my possible being a liar, my business was GONE.
Did rapidly receive a personal letter (not a form letter) and to this day, well over 17 years, I have not received another mileage form request. Some one got their reamed out, and that practice ceased. Check on, ask why, and see what the answer is. What do you have to lose?
Another incident: over a month after another driver had did some minor damage to my tractor, doing about $1500 bucks damage, receiving a ticket, etc., and I was asking for down time allowance while the parts were replaced, and some paint work repaired. It was drivable, but I wanted it repaired, so kept after the company whose insured had been at fault, charged with the accident. Kept getting the run around, until one day when I called, the phone receptionist transferred the call to some one who was attempting to prove his power, and he told me there was no way they were going to pay me $300 per day (a number of years ago) for three days while my rig was in the body shop. Instead, I would be allowed to rent a compact auto, and that was it, and after researching the incident, he wasn't real sure I deserved that.
I told him if I did this, he would have to give me written permission to cut holes in the trunk of the compact to mount my fifth wheel to handle the 48 foot trailer, and I didn't think those 2 little tires would last long, since I normally had 8 heavy 11 x 24.5 tires, but if that was what they wanted, where did I rent this auto? He sputtered some, and I asked just how much time had he spent researching the claim? He refused to answer, but rapidly approved the $900 down time, plus the repairs as well. You must keep on your toes with any insurance company, because when you have a claim, they don't know you, but they sure know you when it is time to pay the outlandish premiums.