Eh...good news is I don't think it's a geo-thing, I was able to switch to UK and buy and download a book.
Bad news, for me, is I think I broke my India connection - switched back and still get the oops...
Maybe I was right and has to do something with the failed pre-order - that book page only shows an empty beige strip, no buttons at all, neither add to cart or see in library. It's...neutered.

(I was able to download a freebie.)
I've just always been wary of trying to contact CS with something like this, assuming they'd want me to 'explain' my globetrotting.