Is damaged phone cable affecting my broadband speed?

[CHT]

I have had a constant 42 thingies of broadband speed for about two years. A couple of weeks ago, it broke. The Openreach man came and had a look inside my house and then went off down the road to fix the problem in a green box. Before he went I showed him where the cable comes up out of the ground into a grey box. The sheathing on the white cable that comes out of the grey box and into my house has cracked and fallen off just where it bends over and runs along the house wall. About half an inch of the 'inside' cable is exposed to the elements. Eventually he phoned to say that it was back on but was a bit slow and things should speed up over the next few days. My speed is now 31 thingies and I received an email to say the speed was below the guaranteed speed and I could leave. I don't really want to leave. Could the drop in speed be due to the damaged cable and if so how would I get this fixed? Thanks

[jamesn123]

@CHT 

Yes the speed loss could likely be the damaged cable. However since Sky have sent you that email this suggests that Sky nor Openreach are not willing to dedicate the resources to look into the problem. This is likely because the UK in general is shifting towards FTTP so fixing older copper lines is becoming much less of a priority.