No -not a typo.
Today, Kobo CS dealt with my request quickly and efficiently and I think they deserve some public recognition.
Yesterday, I bought 4 books, thinking they were new additions to a collection. When I opened them on my ereader I discovered that the books were just a re-issue in four parts of a book I bought 18 months ago.
Today I contacted CS and explained the situation, asking if it was possible to get a refund. The money has been credited to my account less than an hour after I first asked.
Well done, Kobo UK customer service people!
In case of any nitpickers - I was happy to get store credit. It's not a large amount of money and the fault is partly mine. Mostly it's the publisher's fault for not making clear in the description that these books have been available as one volume for a while.