Just spoke to the manager of the store I had the tag hot stamped - Selfridges, London. He apologised and said he will order a replacement - will take 2 months (free of charge). I assume he knows he did a bad job of it. He said he told me it wouldn't be perfectly centred - big lie, as I wouldn't have done it otherwise!
I found it weird that he offered a replacement, as the colour of my bag is last season's collection. Plus I've asked many Fendi staff and they said they do not sell/have spare tags.
2 months wait here we come!
So happy that you could resolve everything!!
