It happened to me, I tried twice and I got an error on checkout both times. I finally paid with PayPal and the order went through, although then I noticed the first 2 tries ALSO went through, so be careful.
I quickly contacted them and eventually got everything sorted (they credited my debit card for the charges), but be forewarned they are in China and there's a bit of a language problem.
I would recommend that you use a credit card, not a debit card. Debit cards are not safe for online shopping.
Why not? I've using mine for years and never had a problem. The transaction still goes through Visa and Visa has called me a few times to verify the activity.
Debit card transactions go directly to your bank account, while the credit card goes thru visa then to your account. You have better account conflict resolution using the "credit" action of your debit/credit card....
