Cable installers can not be on time

On Monday, I had cable phone service installed. I didn't really want cable phone service because I'm really happy with Vonage. But, by adding digital phone to my current cable and internet service, I was able to drop my bill by $20/month. Go figure. So, I set up an appointment with the cable installer between 5 and 7 p.m. This is a much smaller window than normal. Usually, it's like 1-5.
So anyway, I was planning on heading home from work a little early that day to be there by 5. But, I got a call at 4 from the installer saying he was ready to come. I told him I wasn't planning on leaving work that early, and he told me I was the last call that day and he would just have to wait around for my appointment. Not wanting to make the poor cable installer wait, I wrapped up quickly and headed home, arriving at around 4:15. I gave him a call back and said I was home, and he said, "Great, I'll be over in 10 minutes." Well, 10 minutes go by. Twenty minutes. Finally at 5:10 I call him and he says he's getting close. WHAT?!? I think there is something in their contract that cable installers cannot be on time. And early? Forget about it.