looking at the (convoluted mess of a) user manual diagram sheet what is odd is that they do not show direct hookups with 3.5mm for getting audio and only mention it for using the ipod control features.
generally though on most headsets a 4pole to 2x3.5mm 3pole should work fine. since you said it worked fine that would seem to confirm this. my guess would be that you simply bought a cheap adapter cable and it broke or was of poor quality. i'd try a different brand of middling price.
as for alternate ways to connect to pc, the manual does list (a very vague and description free on what is actually supported) usb as a way to listen to music. you could try usb although not sure if mic is supported or not (would be silly if it were not, but i'm not the product designer).
if you wanted wireless, they make bluetooth adapters you can plug into your pc via usb. you should be able to pair with them and use the headphones and mic via BT on your pc. again the (limited) manual offers no help for this other than the standard BT how to connect for pairing instructions (which should work fine)