Beginner Gardening: Something is attacking my Mustard Greens , 0 by Ina_33

Ina_33 wrote:
I bought these Mustard Greens seedlings and they were badly infested with aphids which I got rid of with soap solution. And then some pesky whatevers started invading them. I repeated the soap solution spray; then my garlic,chili and onion potion.
After that I got ugly and started using deadly poisons: Funginex - active ingredient Triforine and Metasystox R - contains oxydemeton-methyl.
I have cut off all the infected leaves in the meantime but am dreading going to look at them again to-morrow.
Picture shows front and back of leaves. Please help!