Listing a new book - clash with new ISBN and existing ASIN

SOLVED: It seems that abandoning the ISBN-13 altogether, putting in the existing ASIN and completing all the other details is the answer. In other words, updating the details of the existing ASIN, rather than adding a new one. Make sure the correct ISBN is mentioned somewhere in the item description. Then it’s necessary to edit it from your list of products (where it will be marked ‘Inactive’), click “Request approval” and then fill in the price, market, etc.

Looking back, this seems to have come up as an issue more than once before; wondering if anyone has ever managed to find a way out of the maze!

I’ve just written and published a book; ISBN 9781838013677. Would love to get it selling on Amazon for the thrill of the one extra copy a year I’d sell and so a few weeks ago I started listing it - to be told:
The value “Digging up the past - A collection of Waterside stories” specified cannot be used as it conflicts with the value " for ASIN Z in the Amazon catalogue. If this is ASIN “1838013679”, update the value to match the ASIN data. If this is a different product, update identifying information

Well, this isn’t ASIN 1838013679; if I understand Amazon’s way of creating an ASIN, it would be 1838013677. Different number, see; all fine. But OK, computer says “No”. Whatever ASIN 838013679 was, it is no longer for sale, and it’s quite impossible to find out what it was.

Pointless to relate the full details of my interaction with the Help department, but briefly:
1: Several attempts to get them to understand what the problem actually was.
2: Can you not see that 838013679 and 838013677 are two different things?
2: No, I don’t own or sell ASIN 838013679, so I can’t go and edit its details, even if I wanted to. I’ve no idea what it is, or was. It’s not my product.
3: No, I’m not going to change the ISBN of my own book, which is perfectly valid for every other book-ordering system on the planet, and is irretrievably printed onto every single copy of the print run, and already registered with Nielsen - from whom I bought the block of ISBNs. It seemed to be good enough for them.
4: Their refusal to help any more, as I have already been offered all the available options.

So, I’m stuck with a book I can’t list on Amazon, because their ASINine system can’t cope with it. It’s no great financial problem, because I’ll sell far more elsewhere in any case, but it’s intensely frustrating nonetheless.

Has anyone ever managed to navigate their way out of this one?