False advertising and shocking service

Shocking, false advertising and then just poor service. They advertise the vehicles for a price of R4799pm and R6499pm over 72 months. So you apply, then they come back and quote prices that are around 30% more expensive and then over 84 months. When you question it they say that it is head office "scheme" that they advertise and the banks do not approve the finance. This is so poor on their part, surely we are entitled to get the advertised price - yes terms and conditions do apply - but when you meet the requirements, meet the bank approval - then why can I not demand the advertised prices?