Replacement USB receiver for wireless keyboard and mouse?

Hi- I purchased an "all in one" computer recently and it the box was missing the USB receiver for the wireless keyboard/ mouse.  Dell Support was quick to send it but they sent the whole setup- including another keyboard and mouse. So, now I have a working set + original that can't connect to anything. 

The parts are not expensive but I hate to throw away a perfectly good keyboard/ mouse if I can get it working on the cheap.  Does anyone know if/ where I can buy just the receiver?  If yes, how might I go about syncing it?  I read online it's possible w/ certain Logitech hardware, just couldn't find anything about Dell.

Thanks!