We had VM installed a few years back then had block paving laid over where we park the cars. Said to the builder "shall I get you some conduit to put the cable in?" "Naw, mate, it's in sand. If it gors wrong, they can pull a new piece through" ....... Never pay any attention to someone like that!
The telephone copper cables (on the out side of the interwebz cable) went down a pair at a time. Called VM who said we'd have to take up up part of the block paving. We said no, we'll keep the Broadband and TV and get phone from Bt via overhead cables
Long story short, when we block paved the rest of the front we put a conduit in and went back to. VM for the telephone.
VM is OK for interwebz, we've been with them since they were NTL, very few problems. Hope you have the same luck