@mrsean93 I believe that the current record for the time between the initial installation date and the date that it was finally installed and working is about 13 months. So yes as @goslow rightly says above, absolutely do not rely on it being done on the specified date, especially once the dreaded ‘external works’ is mentioned!
Can you see if you can’t get your existing provider to move to a rolling one month contact until further notice?
Yes it will cost you more each month but probably worth it to ensure a continuity of service. You might also want to set yourself a time limit, say if VM haven’t managed to install in three months, then you will assume they never will and re contract with Sky.
But do not cancel the VM installation, it’ll either happen or it won’t but if it does, then you immediately cancel within the 14 day cooling off period, but safe in the knowledge that all the cables are in place and working if and when you want to try them again sometime in the future.