Paid sick-days issue

I receive 10 paid sick days per year. last February, I got the flu, and called off work with a temp of 102 and flu symptoms. After two days off, I was called to the office and told that if I called off again, I would be subject to disciplinary policy. Eh? I have almost 30 sick days in my bank and I'm permitted to use two? By the way, I am represented by the toothless tiger/organized crime family SEIU.