The people who did end up writing in are not your problem though, are they? It's the ones who don't. I wouldn't base my experience on the ones who cooperated.
Casual tone is one thing (a good thing), but I posit that an actually angry customer will not respond well to this.
"Oh damn I get this email again... and they are telling me I can cancel, but I think I already cancelled... wth. Hmm, maybe they'll give me a refund."
Now at that point whether the customer is right or wrong they'll read the yell part and think that you are mocking their potential interest in demanding a refund.
Maybe I am totally alone here (with the other guy I guess), but while I wouldn't go dispute a charge myself that wording of yours would not encourage me to write in and get my hopes up you are happy to accomodate me.
Casual tone is one thing (a good thing), but I posit that an actually angry customer will not respond well to this.
"Oh damn I get this email again... and they are telling me I can cancel, but I think I already cancelled... wth. Hmm, maybe they'll give me a refund."
Now at that point whether the customer is right or wrong they'll read the yell part and think that you are mocking their potential interest in demanding a refund.
Maybe I am totally alone here (with the other guy I guess), but while I wouldn't go dispute a charge myself that wording of yours would not encourage me to write in and get my hopes up you are happy to accomodate me.