Failure to repay deposit

After finding out about my cars when searching for a car I decided to pay over a R5000 deposit so that we could bid on vehicles that fitted our criteria . We did and lost the car in the final ongoing and never ending count down . Because of the way this was handled we decided we would not participate again . I requested my refund in January and to date have not received the funds back . I have been corresponding with a guy called Stephen and he is wanting copies of my bank statements and proof of identity . I’m not going to hand over personal information. I have requested a copy of the deposit and to date have received nothing . He gave Me a story it was paid back in March and after checking my bank statement again thoroughly I still don’t see the amount These people are needing to be investigated . If Standard Bank are using them they need to make sure they are not devious with clients as their reputation is on the line as well I await to see what happens in the next 48 hours and I get my money back