Ethical question

[e.e.cummings]

I just received a call from the manager. She said it was actually her who did the transaction! She told me that she really thrown by the fact that I actually called back and that she wanted to show her appreciation. When I originally made my purchases, I had one those 'surprise discount' coupons - you could either have 15%, 35%, 50% - mine was 35%. Well, she said she would revise my entire bill, but this time at 50% off everything (I bought quite a bit). The difference was $19.00! Good karma...