Waiting for installation

If the 14th August date was confirmed as your installation date then that is what you need to work from when claiming compensation. VM will talk about "preinstall" but this is a made-up term, there's no Ofcom-recognised definition of what preinstall means. If VM tell you that the 14th August is your installation date then that is the date you can expect to be using their service - if they have cabling work to perform before this date then they can attend in advance and sort that out (which is often the cause of people having boxes installed on their houses when they aren't even customers), but it doesn't make the committed date given for the installation any less valid.