I was diagnosed with bacterial vaginosis and light yeast infection about 2wks ago.i finished my treatment but green discharge came back.what's wrong?

Recurrent BV? STD?: BV often recurs, so that's a possibility. However, BV doesn't usually cause colored discharge. Were you tested for STDs, including gonorrhea, chlamydia, and trichomonas? These all are more common in women with BV; make sure your doc does the best tests, including DNA test for trich. Hold off sex, or only with condoms. Keep working with your doctor -- it should be possible to work this out.