oxcharts.io

PLEASE HELP! I'm stuck!! Hi everybody, I'm in dire need to crypto brothers and seasoned crypto investors as to how can I get out of this situation, a lot of things depend on this money. So there is this exchange oxcharts.io where there was an opportunity for crypto arbitrage, around 9% on ETH. So I was buying eth via binance and selling it on this exchange. Everything was working fine and seemed well and the platform states it allows 5 transactions per day and it worked until my 3rd transaction, until 4th. While I was withdrawing my usdt for 4th time it gave me this sign and now ASKS ME TO FUND MY WALLET WITH 500USD extra to validate it and be able to withdraw my money. I am feeling so stuck and need a way out, can't think Clearly as to what if this is a scam and I lost my money. This is a UK based exchange and the parent company is registered is what I can see but I don't know what to do. I have around 600 usdt to withdraw but the exchange asks me to add another 500 to verify wallet first.