Here are the pics, i hope these help?
Yes, indeed. We can see the incoming feed (the black cable) arising vertically from the small sealed duct and from the "rats-nest" of wires, joined with gel-crimps are two separate brown cables which clearly run to two separate sockets. (Or, more correctly, one socket (the NTE5/A) and the location (backing box) where an extension socket is desired to be sited.) As all of that wiring is the domain of
OR, I can only say what I might do if it were my house.
However, before I type my hypothetical plan of action, we must clarify one point. Earlier you have said that
"When i put a phone in the master socket it just bleeps all the time." Am I right in assuming that you currently do not use the line for a telephony service? Is it a standard wired telephone that you have plugged in? From where do you hear the bleeps? From the earpiece of the handset? Is the dial-tone audible?
Please go back to the site where you propose to have the extension socket and ensure that all the wires in that cable are separate & no bare ends are touching. Now go back outside to the "rats-nest" and spread the wires out, so that once you have taken another photograph we can clearly see which coloured wires of one cable is connected to which wires of another. My final questions, for now. Are you able to identify which one of the two brown cables supplies your existing NTE5/A ? Is it the upper cable seen to go into the wall in the first picture? Or is it the lower cable, seen to drop down and run to the right in the second picture?