Selling my trade

I just received a customer service call from my mobile phone company, SingTel. They usually call me every year to find out how things are ... well, this time I was told that my free SMS quota per month has been increased from 300 to 500 for being a customer for two years. That was the good news. The strange part was when I was asked about my occupation. I told the lady I was a 'web designer' (mumbling to myself, not for long, not for long). She said, oh okay, so then it's a sales job? I was surprised and said, in a less pleasant tone, "No, it isn't in sales at all". She sounded a little awkward and started asking other questions.