An A320 Captain refused a reserve call out due to excessive fatigue.

Narrative

I deadheaded two legs to my home. While connecting I called the Flight Office and told them my situation; I had not been sleeping very well the past 3-4 nights getting only about 2-3 hours sleep a night. I was extremely tired; and I told the Flight Manager that it looked like I was setting up for a 0300 short call for the next day and that I was exhausted and I would not be safe being available so soon. He advised that I call the Crew Desk and explain the situation; he was very helpful and said to call him back if I had any problems. My flight was leaving for home in a few minutes so I told him that I would call them when I landed in. After landing; I called the Crew Desk. I explained that I was exhausted and that I would be too fatigued to accept that assignment. He said that I was not lining up for that assignment; so just go home and get some rest and see what happens as far as flying assignments and that I might not even get used. He was very helpful and I thanked him. I drove home and at 1330 local I received a message from the Crew Desk assigning me the 0300 short call for the next day. I called back and told her that I had talked to another Scheduler less than a hour ago and said I was too fatigued to accept that short call assignment. She asked when I would be available to be called and I said 0800 the next morning.