"You owe me the money" or "you still owe me the money"
Either is good you can choose whatever you prefer, but still is much more often used if you have asked for repayment of the debt before, or they have owed you the money for a long time.
if they borrowed money yesterday ="you owe me the money"
if you are just handing them the money="you owe me the money"
if you have asked several times="you still owe me the money"
if they did not repay when promised/agreed or asked ='you still owe me the money"