I just received a check from a driveway customer for half as much as she owes me. I charged $60.00 for plowing twice during two different storms. She only paid $30.00 and left a note with the check saying "I have a question. Why did you plow on 1/27 when there was only 2-3 inches of light fluffy snow?" I checked her contract and it says 4 inch trigger, but as I recall we had 4" that day. Is there any official place I can find out for sure how much snow there was? I haven't talked to her yet, so what do you guys think I should say back to that? Should I collect the $30 anyways, or just consider myself wrong? This driveway is out of my way and is only $30 so I wouldn't have bothered to go if it was under 4".