.. 48 hours or more ago I contacted the seller of the ER32 Collet-chuck & Collets and they have not responded.
Amazon has now authorised the return (at no cost to me) and provided a QR code to get Royal Mail to ship it back.
Then, within a few days of it arriving back with the seller I should have all my money refunded.
Fingers crossed.
If they do not refund it then I expect the Amazon A-Z guarantee to kick in and for Amazon to refund my money.
Hopefully, I cannot lose.
However it is a lesson learned, I think I will only buy from UK sellers in the specific field of "Tooling" in future.