Booking.com complaint: not being responded about my contract of renting an apartment

Hi. I got admission for Linz, Austria and about 2 months ago was looking for an apartment for my family to rent as our accommodation. I found an apartment. The owner said she has hired the company booking.com and I paid the money in 2 steps. In the first step one of my friends paid 1235 Euro to the account that they introduced on behalf of me. In the second step, my friend paid 870 Euro.
Now it has been 12 days that neither the owner, nor the office of booking.com answered to my email. The office was supposed to inform me and send me the contract as soon as they receive the money.
The thing is my family has Embassy appointment for July 21 and we need the contract of renting apartment to show at the embassy.
I will attach the payment records. (one is attached as it is not available to attach more.)
It seems that it is a fraud as I got no response in the recent days.

Please help me to receive the contract or pay my money back.
Thanks.