Can't update my contact details

I have been trying to update my details on pnet since some of my details have changed but everytime I try it says my ID is on the system it so frustrating cause I'm on only trying to update my contact details as my number has changed and now recruiters can't contact me if the want to cause I can't update my details I have sent numerous requests to pnet but no response I even thought of di-registering and register again but they don't have such options what's the point of saying they are helping if they are standing in the way of our future..