Kristin Zhivago has an awesome post on her blog titled Gone! The reason customers leave. I would strongly recommend that anyone who touches a customer (sales, tech support, product management, professional services, executives) read it.
I had written last year about how customers are lot more tolerant of a vendor’s mistakes or shortcomings if the vendor keeps them informed. It is nothing but courtesy, professionalism and respect. One of the companies that I respect a whole lot in this regard is CitiCards. Twice in the last 5 years, my credit card has been compromised because of data theft at two retail stores. They proactively called me up, put my account on hold so that no fraudulent charges get made using my credit card. Do I sleep well that they are looking out for me? – oh ya ! Do you think I will ever switch credit card vendors? – oh No! Do you think I will talk great about them and recommend them? – you know the answer to that.
Doing this takes a whole lot of effort and the will to make it happen. Unfortunately companies are busy chasing new dollars, that they forget the adage “Bird in hand is worth two in the bush!”.
Software Product Manager by Gopal Shenoy 
Nick,
I have heard that happen to a friend of mine when he was shopping in India while visiting. It is an embarrassing situation because the store clerk find of gives you that look that makes you look like a thief who stole someone else’s credit card.
Gopal
In my experience one way of keeping customers is for their account manager to be available to them always. If a customer calls a landline or cellphone which is busy he should always be diverted to a Voicemail box that has a message in the salesperson’s own voice.The message should invite them to identify themselves and promise to call them back. The promise to call back must always be kept.
All e-mails must always be answered within a few hours, even if it is a holding reply like “I will get back to you as soon as I have the information you require”
Customers stay happy this way.
Tony http://www.perlablogs.com
In many of the product management roles that I have had, I have campaigned for pushing the boundary of over communication with the customer for service related information (as opposed to marketing and up sell).Sadly with limited sucess.
Your experience with CitiCards was indicative of the process working for you.
I have had a situation where I was travelling and my credit card (not from CitiCards) was locked while I was shopping. This was because MY behaviour was unusual even though it was not fraudulent. While I applaud the bank for taking action I was disappointed when I tried to contact them to find out what the problem was. It was their policy to WAIT until the customer contacted them to resolve the problem. Clearly a frustrating policy from my perspective.
–nick coster