anyone know how pest repellers for bedbugs work?

Tell management you're seeing more than one or two at a time and that the spray isn't working.

Again, the apartment complex needs to treat all affected apartments at the same time. If they don't, the bugs will always come back. Your home is uninhabitable due to infestation and they are violating the law.

As I recall, you are in HUD housing, yes? Check out this information:

Need Help?
HUD handles complaints about housing discrimination, bad landlords in federal housing and many other issues. For additional local resources, you can also contact a housing counseling agency.

Taken from: https://portal.hud.gov/hudportal/HUD?src=/states/colorado/renting/tenantrights 

You cannot get rid of bedbugs on your own. My understanding of electronic pest repellers is that they only work short-term. Sprays can work if they are done by a professional pest control company who specializes in bedbugs. There are NO effective sprays that you can buy yourself. The professionals need to be very thorough and even lift up the carpet edge to get close to walls. However, it can happen that the bedbugs resist the spray and the more expensive heat treatment is needed.  The reason you don't see them in your living room is most likely because bedbugs stay where there is a nighttime food source (blood). They are also attracted to body heat.

Even if you killed every single bed bug, they will have laid eggs which will hatch later and start the cycle again. That is why followup treatments are always done to make sure every generation of the bugs is gone.

Anyone can get bedbugs, but some people are embarrassed about it and don't report it which makes it hard to get the source of the infestation treated. Or they may not see the bedbugs until it gets really bad. If you see ONE bedbug, then you need to assume that there are many, many more. Bedbugs come out at night, in the dark.

If you have bedbugs, every apartment that touches yours (above, below, and each side) has to be inspected and possibly treated.  I live in a condo and we have had two bedbug infestations. The first one, several years ago, was treated with sprays and that worked fine. The more recent one was treated first with heat and then followed up with sprays.  We also had the company bring in a special dog that can sniff out bedbugs and had every apartment in the building checked.

Whoever you are dealing with in your building obviously doesn't know how to deal with this properly. If it is not taken care of, there will be an even bigger, more expensive problem. You need to keep insisting and go over the manager's head if he won't take the proper action.

You can get a heat blow gun and Diatomaceous Earth from Amazon. My friend has success in getting rid of hers with these two items. Professionals use both the heat and the diatomaceous to treat the pests. The only thing is that you have to be thorough and persistent.  Neither one of these are expensive, you should be able to afford them.