Whenever there’s a misunderstanding between you and a customer, you have a choice of how you respond. If I’m your customer and your response leaves me thinking “Really – I’m the jackass here?” (whether I say it out loud or not) – you’ve chosen poorly.
Unfortunately, for a lot of people (most people?) – that’s their reflexive reaction. Regardless of how good your product or service is – if you make me feel like a jackass, I’m not going to be your customer for long.