How Can A Persistent Cough With An Ear Infection Be Treated?

My 10 month old daughter has been sick for the last month now. I have taken her to her pedi 3 times now, and I still don t feel she has gotten any better. It started as a normal cold that seemed to have gotten better after about a week then about 2 days after that got worse in a matter of overnight, so I called the Dr. and they saw her and said it was probably just post nasal drip, again after a few days seemed to be a little better, and within a few days after that got worse again. I took her in again to find she had an ear infection. The Dr. put her on augmentin which she had a reaction to which gave her a terrible diaper rash so I called once again and they changed her med to azithromycin and probiotics. I still see no change in her cough..it is a frequent cough that at times gags her. I am very concerned that she should have gotten better by now. What should I do?