Yikes. Bedbugs are bad news. I once slept in a "hotel" in SF that was littered with them. I went and got trash bags and covered everything I touched with plastic. With some careful quarantine procedures, I miraculously didn't bring any back. If you haven't already tried: bedbugs don't handle heat too well (eggs neither). They are weaker than pets and babies. You could stuff all your possessions into a car, seal it up, and park it in the summer sun somewhere for an afternoon to be rid of them. The ones in the car at least.
Alas, we've already had our entire unit heat treated once and sprayed twice. The exterminator that did it offers a 6 month "guarantee" so the subsequent callbacks have been free but he hasn't exactly been confidence inspiring to deal with. Our lease has a clause where the tenant is responsible for paying for treatment. And the guy they called out was more than a month's rent. So I wouldn't be too surprised if someone else in the building had them and was staying mum about it. ¯\_ (ツ)_/¯