unable to withdraw

I invested last year, and made profit, and they made me pay 20% on earnings which I had to send them because they didn't want to deduct from earnings, after paying and waiting more than a month I did received an email saying withdrawal successful but I never received the money, and since then I keep trying to contact them and once I give them my email they stop answering me, I send them 30k US dollars and made a profit of 16k, and paid 3.3k to withdraw and nothing until today