Is there not a RM ombudsman? Are you NOT able to challenge their initial response?
I've had to collect scores of parcels from the local depot, the card would show my name, parcel the same. My wife has collected each and every one of them on her way to work and never has she been asked for ID.
We once had RM SDE containing passports and Indian Visa left on the depot shelf, we contacted the high commission and was advised that passports had been returned 4 weeks earlier, we did a tracking and they had been signed for by someone else unknown to us. Next morning we went to the depot the RMSDE was on the shelf. RM stated they'd come to deliver and left a card then 2 weeks later came back to the house and obtained a signature! My reply was, if you obtained a signature why did you still have the RMSDE on the shelf gathering dust?
I've had recorded delivery stickers peeled off packages and the package left in my open porch, I've delivered dozens of letters to neighbours when they've been put through my letter box in error. Only last week I was talking to my neighbour when the posty came along, handed me some letters, the same to my neighbour. I had my neighbours letters, she the next door down and the posty had to go back to the house the other direction to retreivemy mail! Shambles