StAdens Internalnational dont want to repay me.

In 2013 St Adens International were selling a house in Tembisa Birch Arches.Tirhini properties was their middle man . I paid a deposit of R40 000. When the Bank valuated the house they said that house was over priced it doesnt worth the R400 000.00 they were selling it for. I sent them emails from the Bank regarding the price of the house. They then went behind my back and sold the property to someone else without my knowledge, meaning they got two deposit , from me and the one who got the property. All I want is my R40 000 back nothing else. I have sent them several email but still am not getting my deposit back. I believe they are greedy for taking 2 deposits.