In Waterstones, buying a couple of books as a present and a book token. Paid and not offered a bag, when I asked for one "Well I will have to charge you, you should know that by now"- scrape about for a 5p in my purse, can't find any change so tell her I'll put them in my supermarket shopping bag "It will probably get lost in there" she told me about the book token.
Not exactly helpful, and I think quite rude! Why not ask if someone wants a bag before charging them? Argh.