Why isn't this going away?

I went to my doctor to ask about a vaginal bacterial infection. He told me to use Monistat, which didn't work. I went back and he put me on some antibiotics for 7 days, which didn't work. I went back he put me on a 7 day vaginal cream, which didn't work. I went back, he took more tests, and I am still having the same exact symptoms yet he is saying everything is normal now? I'm still having a foul smelling discharge and it's really bothering me. Why hasn't it gone away yet?