@OneYankeeRebel: At first I did have a problem with the mic in my webcam, in game it would pick up my voice and was really distorted. So fixed that problem by disabling it.
In the end I did what Frosty suggested; of course I decided to do it just before the Koth match and ended up with no mic in mumble or in game. Then I realised that the mic was muted in the Sound control panel when I muted it in the Creative Launcher, so at least I could talk in game but mumble was still not working.
After some tweaks and getting all frustrated Frosty found out what the problem was. I just needed to set the Device to Devault Device.
So yay, it works.
Thank you all for your help