beware of false advertising

So they advertise that they offer monthly cash deals on windshields starting from R800 - so I ring them up, give them the vehicle details and get an absolute great price of about R1400 and ask them to send me a quote before making the booking, no quote received, I call them again and this time with the vin in hand the price jumps to about R2400 which is getting crazy but then the branch phones me and says the price is more than R7000 - so this has been an absoluut waste of my time. beware of false advertising