Alright, the good news is that I've made some progress, (turns out the SIM card wasn't properly inserted at first, my bad 
) I now get a ppp0 interface and it is being given an IP address by my network operator.
The bad news is that I still do not get an internet connection through the gateway.
I checked /usr/sbin/iptables -nL and found that it was empty (aside from Chain INPUT/FORWARD/OUTPUT etc), not a good sign.
Checking the logs I found: daemon.warn pppd[2051]: Could not determine remote IP address: defaulting to 10.64.64.64
So it appears that the routing is not functioning properly, or not activated at all.