PROGRESS REPORT
I contacted Hermes, they were useless. They said they did not have any contact info for their couriers, but even if they did, they wouldn't be allowed to tell me because of data protection. They said I would have to go via QVC.
I contacted Q again and got someone more helpful, and came to a satisfactory arrangement, which I may tell you about if this all works out.
In the meantime, the item has NOT come today so far, so it seems it was not a mistake by the courier.
If it doesn't turn up, I am quite serious about getting a crime number from the police, to give to Hermes and Q, because it is about time all these mysterious non-deliveries are properly investigated and someone is held to account.
They will be sending me "the letter" but I will then try to get it done by email, as suggested above.