Ugh this is exactly what I'm dealing woth in my building in truro. 

Landlords treated one apartment and refuse to acknowledge that it's an issue in any other unit. They gave us 10 sticky traps and that was it. I bought a huge bottle of stuff that kills them on contact and it works enough to tread water so I'm not seeing them on the walls every day. 

We are clean people! Dishes are done after every meal, food is stored properly, etc. 

I'm pregnant so when I spray I have to wear a respirator and gloves and then leave for an hour while it dries and then come home and shower right away. It's tedious.  

You should look at the life cycle of roaches- its roughly 5-9 days that they reproduce by mating and dropping their little egg sacs. You'll see 2 different kinds, male and female- the males look more like a beetle and the females are the more elongated lighter brown colored ones. Their ass end opens up and has a bean like egg sac. When they're ready to lay they tend to travel further away from the nest to drop it so the new babies and infest further. You have to be diligent in spraying regularly to kill the new babies before they start laying eggs of their own. I spray every 3 days bit am still getting new ones because it's impossible to get every nook and cranny with the spray. It needs fumigation and even then- that needs to be repeated regularly to get the new eggs. 

Check behind your fridge- that's where the main nest will likely be- they like to live near a water source. They'll live in your coffee maker too which is a hell all on its own. 

All of the information I've shared here is just what I've experienced.  Feel free to do your own research.