I had chlamydia took 4 pills of azithromicyn after a month went to re test and came back positive. i did not have sex during that time. what's wrong?

No big surprise: Azithromycin is very good against genital chlamydia, but not perfect. The cure rate is around 96-98%, so it fails in roughly one in 25 to 50 patients. You don't say the anatomic site of your infection, but azithro works less well for rectal infection, failing to cure 10-15% of patients. Recently STD experts have begun to recommend primarily doxycycline and not azithro for rectal chlamydia.