Virgin Media refused to send me details of the pre-planned work and how far in advance they approved the works to go ahead. It's not included on my SAR as they avoid sharing too much information with the call centre agents.
CEDR couldn't be bothered to ask Virgin Media to evidence that the work was planned in advance. (I found the service a waste of time, but I guess they can't bite the hand that feeds them)
CAB have advised they will need to provide the information at court. Thus I'm taking legal action.
Do you know how I could get hold of the information? I might try the council as they may have a record of when the highway permit was submitted.
CISAS would not carry out an investigation for you and seek out evidence. The last CISAS stat's report that 83%-ish of cases were 'settled' or 'found in favour' of the customer. If your CISAS case was unsuccessful it would be in the minority of outcomes.
If your issue is to do with the automatic compensation scheme for a loss of service, there are clauses in the OFCOM minimum requirements document and in VM's T&Cs which halt payments if VM gives advance notice of works which cause an outage (VM's doc's say not less than 24 hours notice).
Some topics on the 'Quick Start' forum do mention customers contacting their local highways authority (may be your local council or county council) to find out information about street works. In these delayed-installation cases it is often when VM is claiming a delay in installation is due to waiting for permits to work from the council. The councils on those topics seem to have been readily forthcoming with the information when they have been asked.