People are fond of saying that they are brutally honest. Honesty is good. Being brutal about it may not be. Confrontational honesty may be counter productive. You don't have to be brutal to be honest. Being polite is more likely to bring about positive change. Remember when your mom told you to count to 10 - first. Present your issue in a calm and factual manner while staying courteous. People are more likely to listen to a complaint when it is not confrontational.
A few weeks back, I had an 07:00 appointment at a Co op in central Wisconsin. They allowed me to park overnight there. The customer was located in the downtown area of a small town. Great, I could take a nice walk and have dinner out. There was a baseball game on and I might watch part of it. It was really nice of them to let me park there overnight. As a matter of fact when I got there, they told me to go ahead and park in the dock. They only had one dock. That way, I would be first in line in the morning. I appreciated that.
Around 06:30, I checked in. They were loading their delivery trucks. They showed me a place to get coffee. They were nice, but also told me that they would not get to me until a little after 07:00. At about 07:45, they still had not started me yet. I checked into the office and asked when they would get to me. The woman in the office said that she would let the fork lift driver know that I was there. About 5 minutes later he yelled out the door for me to "open up" and left. This was a sealed food product load and I wanted to make sure that they saw me break the seal. I pulled the truck up a few feet and stood at the back with the bills and waited for mim to return. When he did I asked if I could break the seal. I did it in from of him and then backed the truck up to the dock/
It only took him about half an hour to unload the truck once he got started at at 08:00. At that point he brought my bills out to me and I got out of the truck as well. We had a conversation. He expected me to be angry. He told me that he had faced many angry truckers ove the years. They were angry that they were told to be there at 07:00 and when they showed up they had to wait unitl after he got his delivery trucks loaded. - around 08:00. He had asked the office people to let drivers know that he would not get to them until about 08:00. Word never seemd to get back to the drivers. I told him that yeah, I would rather have been empty an hour earlier, but that I had much worse over the years. I told him that I would get a half hour detention pay. He thought that was a good thing, and he hoped that his company would get billed for it. I told him that I would ask my company to ask if the appointment was really for 08:00 and not 07:00 and he said that he would once again ask his management to set the appointment up for 08:00. Maybe, by having a polite conversation we could actually fix the problem.