You are only supplied with a short cable as long cables affect signal levels which require an engineer to adjust. VM don't make clear that only short cables are supplied, & if you need anything over & above this a manned install is required. I would phone up & explain the situation & they should send an engineer out to make the alterations required.
Just to point out that the coax cabling within your property forms part of the local network, & any modifications must be carried out by VM, or all kinds of issues can result.
Cable customer since 1993. Services: FH TV, Sky Sports & Movies (2xV6), Talk Anytime Phone, VIVID 350, Virgin PAYG Mobile