Still no resolution to this despite multiple calls to customer service.
The pre-installation team told me that a third party engineer would come on Thursday to redo the external work. I waited in all day and no one came.
I called this morning and the pre-installation team told me that they would email the company that does external work. They said they had no idea when the work would be done and would not provide me with contact details for the company doing it so I could follow up.
I was told the engineer would still come to do internal work today despite the external work not being completed. They would waste time driving out and I would have to waste time waiting in for their arrival. Apparently there is no way to tell them not to come even when there’s nothing for them to do.
I still have no indication when this will be resolved and cannot tell my neighbour when their wall will be repaired.