The World of Little Little Bird

I purchased something from amazon.com the other day. The total was 33.98-0.53(1.57% A9 discount)=33.45. Today, I found the price of that stuff went down 2 bucks. So I made a phone call to amazon for a 2 dollars refund. An Indeian CSR issued me the refund immediately. When I checked my account just now, I found that only $1.47 was refunded while they wiped off all the discount, which should not be the case. I called again. I tried to explain to the lady that they shouldn't have pulled of all my coupon but only 1.57% of the $2 refund. However, she simply didn't get the maths and repeated that was how they do refund. The phone was suddenly hung up rudely. To my surprise, when I refreshed my order page, I found myself issued another two-dollar refund. Sigh, what can I do to stupidity?