wammu-configure: 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/wammu-configure - from package: wammu

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