excellent customer-service-that-rejects-plaudits practice

I recently noticed a payment for £1.55 to Amazon on my credit card statement - as I have an order outstanding [waiting for availability on a new book] I assumed the that the payment was related to that order, so I fired off an email questioning it [I'll not mention that finding the 'right' contact page was tricky].

Within an hour I had a reply pointing out that the payment related to a different purchase where I had used a gift certificate, and the £1.55 was the sum over the value of the certificate.

Hmmm, 'plonker - that's my mistake', I thought, and sent an email back apologising for wasting their time, and thanking them for the prompt response. Sadly, the following immediately appeared in my inbox:

Couple of points:

1. I can appreciate that they need to keep incoming emails to a minimum, but what if I wanted to query their response?
2. It must be a harsh place to work where you spend time dealing with idiots like me, but are denied the 'nice' stuff complimenting you for your efforts.

BTW - I was on amazon.co.uk - in the UK we spell 'cancelling' with two 'l's. Small point, but worth getting right.