[InfiniTy.]

Well what you have there is checking if YOU are banned and not the username that you've typed ..and also

Код:

This user doesn't exist.

If you type a user that exist in DB but doesn't have Banned = 1 it's gonna say the user doesn't exist.. but he does.So you need to change that text
Also .. if you have sscanf ..why not use it ? In commands i mean.. if i'm not mistaken zcmd+sscanf are the fastest in terms of commands