So after 1.5 years, I decided to repay the money I hacked from this user. I have sent the exact amount of BTC regardless of BTC price [It was 20~21$ and now it's almost 500$].
Here goes the transaction: https://blockchain.info/tx/827e45cb166cc6d1746bedca4b73c77e1a59b00707a23b25c411f884707e63d7
https://blockchain.info/address/1LuQxE82nZoT2YPqD943zG7zK5dwjiU6Q2