smstrade_balance: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/smstrade_balance - from package: python-smstrade

You may install the required package with command apt-get install {package}
Error in other languages:
smstrade_balance: bevel nie gevind nie
smstrade_balance: comandă negăsită
smstrade_balance: comando não encontrado
smstrade_balance: commande introuvable
smstrade_balance: command not found
smstrade_balance: käsku ei ole
smstrade_balance: không tìm thấy lệnh
smstrade_balance: komanda nerasta
smstrade_balance: Kommando nicht gefunden.
smstrade_balance: kommandot finns inte
smstrade_balance: komut yok
smstrade_balance: nie znaleziono polecenia
smstrade_balance: níor aimsíodh an t-ordú
smstrade_balance: no se encontró la orden
smstrade_balance: no s'ha trobat l'ordre
smstrade_balance: opdracht niet gevonden
smstrade_balance: parancs nem található
smstrade_balance: perintah tidak ditemukan
smstrade_balance: príkaz nenájdený
smstrade_balance: příkaz nenalezen
smstrade_balance: команда не найдена
smstrade_balance: командата не е открита
smstrade_balance: 命令找不到
smstrade_balance: コマンドが見つかりません