Unacceptable business practice

I recently needed to replace my broken window glass and I called them. They said they would come over my place to measure and provide a free estimate. I set up a schedule with them in the evening but no one showed up.

A day after, a customer service rep called me and apologized about that claiming that they were so busy last night. But the problem was that they didn't call me to let me know they were not coming. So I gave them a second chance by scheduling another appointment in the same evening. The customer rep told me he would make it up for me. But then nobody came and no phone call about why they not coming.

This is totally unacceptable business practice.