I had aline installed in February and have not received a bill for it. The guy who installed it said i might not get charged because the builder has in fact done most of the work and all he had to do was connect it up. If your house is only 7 years old, is there any possibility some of the work up to the house may have already been done? Maybe ask a neighbour....
I was told when ordering the reason why BT charge such an amount for installation and they stated they allow for 3 hours worth of technician time