Use a systemic insecticide: it will take care of whatever is feeding on your plants. If you have concerns about pollinators, cover your plants with a fine mesh for 7-10 days until the active principle has broken down.
You can use an agri mineral oil (soap is more miss than hit), but remember you need to drench every part of the plant in it: since it's inert (it kills by forming a thin film over insects, chocking them to death) it needs to cover up the insects you are trying to kill. Unless you drench a bee in it or something, it is completely harmless for them.
A word about those "biological control" you purchased: save your money next time. Plainly put these beneficial insects are not obedient little machines that will instantly set to work the moment they re set free. More often than not they just disappear in under 24 hours with no effect whatsoever, often themselves the victims of a higher level of predators (mantises, birds etc)... well, no effect apart on your wallet.
Even when they exist in nature and do their job, they often struggle to keep pest numbers under control, for the simplereason creatures like aphids evolved precisely to literally overwhelm predators through extremely high numbers and fast reproduction rates.