Which antibiotic is best to treat human respiratory infections like bronchitis ?

I am sick with something similiar, well is bronchitis, I became unwell 3 weeks ago, was first put on augmentin 500mg X 2 daily but after a week no improvement so was put on Klacid 500mg X 2 daily plus steriods, 60 5mg tablets to be taken in 10 days! So I was on 8 a day for 3 days then 6 a day for 3 days and so on! I've 4 days left to go bit still am very sick!