I received a service from a Cosmetic Provider. When I left, I was given a chit of paper which had the price on it of $279. I went to the reception and paid the amount that she said was to be paid, which was the amount we both read off the chit of paper. Payment went through and was confirmed by my receipt and also at a later date has been confirmed with my statement. Four days later, I received a phone call from the provider's office to say they under charged me and that I need to pay them another $500. The chit of paper should have been read as being $779. Not my error, as I was never given a written quote or any price discussed at the time of service. I told the caller that I thought it was ludicrous to be able to change the price at a later date when I paid in full on day of service. I'm now being sent threatening accounts and a letter of demand with pay in seven days or legal action. How can the provider decide at a later date to change the price then pursue me legally under Australian Consumer Law? It's becoming harassment.