You are stuck until VM gets its act together with the cable installation sub-contractors and completes your installation or VM gives up altogether and cancels your installation.
You should start keeping a detailed record of events (dates, times of all calls, messages, texts etc. along with any missed appointments and failed appointments where someone turns up but no work was carried out). Keep the record in a timeline format with links from the timeline to each piece of recorded evidence. This will make it easy for you in the future to put forward a case to arbitration for the correct compensation, should that be necessary.
https://www.virginmedia.com/help/billing-and-payments/automatic-compensation
Do you have a working connection from another provider at the moment?
If not you should be considering what temporary measures you can put in place to give you some connectivity (a temporary Openreach connection on a rolling 30 day contract or an unlimited data SIM on a rolling 30 day contract).
You are unlikely to get any useful info from VM that you can truly rely upon and help you plan what to do.
Go through some of the (many) delayed installation topics on this forum and you'll soon get a good idea about VM's general patterns of behaviour in such cases.
