Fxuniversaltradeから撤退できません

I was told that I can invest with the minimum amount of R500 after I transferred the amount of R500 worth of Bitcoin to their platform they told me that it was insufficient and I have to top it up with R900 they contacted me after two weeks telling me that they managed to trade with the minimum amount I paid but I need to pay the balance of R900 for them to pay the profits to me