19 Bella Vista - pay back our deposi

We booked for a place called Bella Vista through Booking.com for the Easter Weekend. After we paid for the full amount that was required they sent us an email with an invoice attached 2 days before our trip telling us we need to pay a refundable R1000 deposit more as the guests that were there previously broke things and left the place messy. We already had made arrangements and we had no choice but to pay the money as inconveniencing as it was for us. They said we will get our deposit 7 days after we have left, until to day they have not paid the money to our account. We have tried to contact the lady by the name Sonika and she is been saying tomorrow tomorrow