HDFC Bank — Deduction of money without my knowledge

Hello sir,

I have deposited 50 USD in IQ Option ( Trading app) on[protected] on day time and I withdraw the same amount 50 USD from IQ Option to My bank account[protected] night). After 2 days[protected], I received my money and after some time it is automatically deducted from my account without my knowledge and there is no reference number, nothing mentioned .it is not credited to my iq option account also, where the money gone I don't know. Kindly solve the issue. I have tried to contact your customer care but they are also not picking. I'm NRI, now in Saudi Arabia . So please help me to get out of this issue .