I recently went through this on a series of purchases where I got that error message but was then charged for a book I didn't get. It happened after I bought a gift card in the Aussie store (that charge worked for some reason). When I returned "home" I kept getting the error message unless I used the gift card store credit.
Customer service was good about getting me a refund...but it took a while for them to agree to reset my account. I think customer service may vary depending on where you are calling from (seems very good in North America).
good luck!
Quote:
Originally Posted by Lynx-lynx
Kobo has declared that my Credit Card can't be processed:
'We were unable to process your request at this time. Please try again.'
The failure to accept occurs at the point of entry in the Payment Information section of My Account.This isn't the first time that it's rejected my card.
I'm still waiting for someone on Live Chat to respond. The 'message 'searching for an available agent' has been going on for maybe 10 minutes now, so I don't hold much hope of reaching them this morning.
Once again I'll ask them to re-set my account at their end, and once again I'm sure that we'll go through 2 to 3 days of them telling me it's something else or other before they finally agree to re-set my account at their end.
Once again they'll tell me to just pop out and buy one of their gift cards and use that because then they don't have to worry about sorting out their stuff re card failures at their end.
This just becomes so wearisome!! 
Well, enough of being down I say .... enjoy I say! 
Edit
For those who may not know about Live Chat here's the link:
Front Line service |