I was one day late, and they started calling me first thing in the morning. I was still lying around drunk, and they were already calling me at 9 o'clock instead of a wake-up call, wanting to hear a reasoned response. What can I possibly say when I just went to bed an hour ago? But if I ignore them for too long, they'll start charging me a penalty. I don't want to take that risk. After the calls, I remember and go pay.
