We had an agreement that the guy will come to put the devices in both my cars today

We had an agreement that the guy will come to put the devices in both my cars today. Surprisingly, he only brought one device and has asked to come another day. Why coming in first place knowing he didn't have two divices for both my cars. This is unprofessional and waist of my time. You need to plan things properly before waisting other people time. This is a bad impression on the first day of rendering a service to anew client. Until you prove me wrong in the future, this is the image of your company in my mind.