Why make promises you can't keep?

As someone that works in a client service center that has great service, I have a problem dealing with poor service. I have been waiting for my glasses longer than the stipulated 8-10 days. That's not the issue, the issue is that every time I call, someone promises to get back to me and EYE as the client have to continuously check up on people who promise to call me back and don't.

As I type this, I'm still waiting for glasses I ordered in mid-January.