You only read about things like this in the Dos and Don'ts Section of "Designing e-Commerce Web Sites for Dummies" and never expect it to happen to you. Unless, of course, you're trying to make an online payment at Dish TV's web site.
I tried to renew my subscription there the other day. While I was at it, I also wanted to see whether I could add the Star TV channels to my account (yeah, I know I was asking for too much, after my earlier experience, but what's life without hope? Anyway, I had had my confidence somewhat improved by talking to a customer service rep who advised me over phone as to which option to use for the renewal/upgrade.)
I did all the things I was advised to, including entering my credit card details, but instead of getting a "Transaction successful" message, I was informed that there was an error. I had faced this kind of error before (if I remember correctly, I think I was asked to try again after 24 hours, for whatever reason), so I wasn't overly concerned -- this was, after all, Dish TV I was dealing with -- and logged out.
Twenty-four hours later, I reentered my transaction, and it went through. This time I didn't opt for the everything-and-the-kitchen-sink option, but just a regular renewal, so maybe that had something to do with my success.
Cut to me reading my monthly credit card statement three weeks later; there are two back-to-back transactions billed against the same merchant. The transaction amounts didn't look familiar, and I fired up GnuCash to refresh my memory. That's when it hit me; the earlier of the two transactions was the $^%& 'failed' transaction.
The only saving grace is that my Dish TV account has been credited with both the amounts. Thank the Lord for small mercies.
Rubbing-salt-into-wounds addendum: Today I found from my friend's mother that Tata Sky doesn't have any problems functioning when it rains, whereas I have been blessed with 'No Signal' messages from my Dish $#%^ TV receiver for the past three years whenever the satellite dish looked at the cloudy sky and decided it didn't like what it saw.