Really need your opinion

I just need your suggestions or comments please...
I am working in a restaurant as marketing. We are engaged in a catering services. The thing is i just booked a wedding party with us and we are the one who needs to serve the food and find a place. On the very last minute the venue which i booked in doesnt want to go with my booking he says that they cant do it. Now of course since i dont have a new venue i called the couple and told them what happen. they told me to find a venue for them coz the wedding must go on. So at the very last minute i found this hotel and do the booking thru phone. I even told the couple that i found a place or a function hall which cost QR 4000 and the food cost Qr 18,400 cost they told me that it is a hotel and we cant bring in the food from our restaurant. I asked the Groom and told him how much the price and he says go with it.
Now the thing is like this the total bill cost QR 22,400.00 the couple says the i need to shoulder the payment on that hotel coz this is my fault because the venue that i found was cancel and i told him i cant shoulder that big amount coz it is a lot of money so what he says is he will shoulder the QR 12,000 from that amount and i need to pay the balance of QR10,400. Now my questions is this Do i really need to pay that amount? I didnt sign any contract from the hotel nor the guy who works there didnt asked any cas advance on that one. Do i am really responsible to pay this big amount??? Please help me????