I've sold on the intenet for 10 years and have taken credit cards for at least5 or 6. I have never had a charge back yet. I know it will happen - but my point is that it should definitely be the exception. If you start to have a lot of them then I would look into it further.
I'm with you on the refund. For $12 it's worth it to just refund the money and not go through the headache. The time alone would cost you a lot more than $12. I have had a number of times where customers have questioned things (item didn't arrive, etc.). I tend to believe the customer MOST of the time - unless I have proof of delivery etc.
I did have one large order that the post office delivered to a neighbor instead of my customer. I knew it was delivered because it was scanned. However the neighbor didn't give the package to my customer for WEEKS, so we had no idea this is what happened. Even though the order was higher ($60 or so) - I reshipped the order. Finally the neighbor told the customer they had the package and the customer returned the duplicate. I was out the extra shippping - but prevented a chargeback and kept the customer happy.
Unless my gut tells me I'm being cheated (or the order is very high) - I usually believe the customer.
I have had the Nigerian orders where they want 50 pieces of jewelry etc. and need it shipped immediately. I just kindly refuse those orders and don't process them at all. Once you've been in business a while you can usually start to see when things seem odd.
Good luck
Cekman
www.cobwebcorner.com