No solution for aphids?!?

Long story short I purchased a bag of soil I did not know was contaminated. I've had a seriously bad aphid infestation and these are INDOOR plants! I have tried the dishsoap water, I repotted all the plants and cleaned the pots before hand. The dawn dish soap did not stop the aphids at all!!! Or the gnats!! I tried organicide and it does NOT DO ****!!! I tried peppermint oil water, it hasn't done anything to stop/kill them. I dont understand are these ******* mutant aphids or something?!?! I dont want to use harsh chemicals on these plants to stop the aphids. Why aren't these solutions working?!