I suggest you try to get the package that was partially installed either removed, or then have apt/dpkg "reconfigure" itself to forget what it was doing; it might be you need to manually delete the files, and I guess the *easiest* way of doing this is to obtain the .deb package from somewhere, then manually install it (force, if needed) and then remove it, if needed. Apt indeed is tricky when it comes to unfinished business.. the lesson? If you ever install something that deals with kernel - drivers, that is - you should use the "download only" option first when running the apt-get command, and once it's done (files downloaded that you need), re-run it and have apt install the already downloaded packages from cache.
To use bcm43xx chipset for your wireless networking, you have three choices: ndiswrapper, bcm43xx-fwcutter and b43-fwcutter. In reverse order. The b43 driver (b43 and bcm43 are the drivers that are included in the kernel; which one, that depends on the kernel version/packager) is newest and works at least as well as bcm43xx; bcm43xx is it's "older brother", and ndiswrapper is the "overall" solution for wireless cards that don't have native Linux drivers. You'll need the Windows drivers in any case - if you use ndiswrapper, you'll "install" the Windows drivers using ndiswrapper, and use ndiswrapper as the driver then (and blacklist bcm43xx or b43 to prevent it from interfering). If you use bcm43xx or b43, you'll use the fwcutter-tool to "chop" the needed parts from the Windows driver, place them on your system and have the driver work as if it is fully native (it is, except for the parts you need to extract from Windows driver). I recommend bcm43xx or b43 (depending on which one Debian provides), as they are less likely to give you trouble - ndiswrapper works, but at least you don't need to deal with blacklisting, and upgrading is easier, if you don't use it
So: try to get the bcm43xx package from somewhere if you can, re-install it, then either use it or remove it. Once you've dealt with that business (not sure if dpkg's package reconfiguring helps, you may try), decide if you want to use ndiswrapper or bcm43xx (I guess b43 isn't in Debian, as you mentioned bcm43xx only), then fetch the correct Windows drivers for your card and either ndiswrapper or fwcutter 'em, and in case of ndiswrapper remember to blacklist bcm43xx. That ought to be it.