I don't know what to do anymore

I joined JustYou Agency last year. This year in February I attended two shoots for them as an extra. Each to pay R600. I was paid for the one day beginning of May and I have not been paid for the Second day. I am being told that the money was paid on their side. But I have never received anything. The other artists were paid the entire amount in one day. This is their Number: **********