Honesty is not the best policy at this guesthouse

I'm really not happy about the service they offer. I booked online for 4 individuals at R3600 from their website. Today when I arrive they tell me I need to pay another R1200 that I really don't budget for. It took them the whole 3 weeks to figure this out when I arrive whilst I spoke with them they said everything was good. I'm really disappointed at our christian ethic.