No way to determine whether or not the system is hacked based on the information provided.
The modem may be bad- which is causing the phone call to hang. You may have to send it in for repair or go install turbonet to make the daily calls via broadband.
edit: if you are using the modem and there is no turbonet card installed make sure there is not a dialing prefix set in the phone options. Did you rerun guided setup when you took ownership of the unit? Are you sure you answered all the phone questions correctly?