Note or phone

Arriving at my desk I saw the light on my phone flashing. I have a message. Did someone complain about my attire? Did someone notice how long I had been gone? I checked the caller ID. It was a call from my department head. What had I missed? Was I going to get a reprimand, fired? I can't believe I let my roommate talk me into this dare. I can't believe I got so involved in returning the dare I was away from the office for so long I was missed. I check the note on my desk. It is from the receptionist. It says "I covered for you, I'll collect later, Colleen". How did Colleen plan on collecting? Who do I contact first The Department Head, or Colleen to find out how she would collect and what I missed?