I understand wanting to have your own style. I am not opposed to the casual tone. You were complaining that some customers don't take you up on the offer, and instead contact their banks to request a charge back. I was suggesting that changing that one word (but not necessarily the casual tone) might make a difference in encouraging some of those people. But it is your business, you can try the suggestion or not, I apologize if my comment came across as pushy or anything like that.