The rep couldn't stay on the line with me because she'd exhausted her "commitment time." What does this mean?

I called my health insurance company with a question about coverage. The representative put me on hold and attempted to research it, coming back several times to apologize and say that she was still waiting for information. She was very courteous about it. I’d guess she was on hold nearly as long as I was.

Finally she returned and said she couldn’t wait any longer because she’d used up her commitment time for today and wouldn’t be assigned any more until tomorrow.

What in the world is that about?