i have used some software for bluetooth hack, but every one of them also require authentication from victim phone.
but once you get it you are all good to go then. every thing will be in your control,
even if you call from your phone, balance will be deducted from his/her sim card.
not axactly you are calling from your phone, but you are using victim mobile to call over bluetooth.
don't know that much about AT command.
but, i always have to use it when i try to connect internet on lapto using my samsung mobile.
i have to type this command
this command just use given apn directly insted of looking in your mobile profile.