DEPOSIT ADDRESS NOT USED

[pedram1995kzm]

hi
i'm trying to generate deposit address for each account of my website users
I mean imagine there is 2 users in my website and one of them wants to deposit BTC
so when he clicks on generate address
code runs :
PUT /balance/deposit/address/BTC
but he hasn't used this address yet
suddenly next user wants to deposit BTC too and then code runs again:
PUT /balance/deposit/address/BTC
but it says
{
code: 318,
data: { },
message: "Deposit address not used."
}

any solution?
if there is no solution for this issue, how can i make an exchange with this api?
any idea?
I really don't know what i should I do :( help me

[pedram1995kzm]

??