If you are a new customer to Virgin and don't have a Virgin connection to your property you should have asked for a manned installation which would be free. You can either call Virgin on 150 from a Virgin phone, mobile or landline, or wait here for one of the forum team to pick this up which might be 2 to 3 day's.
Is the coax cable just a TV aerial coax, a quick guide would be if it's a Virgin coax it will probably be white connected to a wall socket, (you would also have an external box connected to the wall outside), a TV aerial cable is usually brown or possibly black.
If they do charge you it will be £25.