i have a problem

ive been through about 5 lots of new phones in the past 2 yrs and i think thats a bit excessive...the ringer has gone on 2 of them,2 have had unknown faults but have just stopped working,and the latest which is a week old and cost £120,when you press call button all you can hear is bad interference noise and nothing else.....i know your not supposed to touch the box coming into house but i want to go through all my connections in the house to make sure they are correct...i have 2 wires coming into the house which are both black... in the box they are joined to a solid blue and a white/ blue striped cable which go to a normal bt socket to pins 2 (white/blue) and 5(blue)....question is does it matter what way round the 2 black wires are that come into house,and also what numbers in bt sockets and colour combination is correct??? any help appreciated
regards mark