This is not something the forum team can help with, you do need to speak to VM to change your package. If you call 150 and take the "Thinking of leaving us" option you should get through to a UK call center (during UK office hours) and they can help you arrange a new deal.
The broadband package you are on is a legacy package that no longer exists for new customers, so that suggest you haven't negotiated a new deal with VM for a wee while. The current Full House bundle with Vivid 100 is listed on the VM site as being £74 a month after the new customer promotion ends. That would get you faster BB and a new V6 TV box that is miles better than the old Tivo for a bit less each month. That is the bare minimum that the retentions team can offer but they should be able to do better.
Disclaimer - I don't work for Virgin Media. I'm just another VM user trying to help out. My setup: V6 TV box, Vivid 200 Optical fibre with Hub 3 in modem mode connected to a Netgear R7000 router. Telewest/VM user since 2001.
As a Very Insightful Person, I'm here to share my knowledge. I don't work for Virgin Media.