Are you using a router? If so, unplug it and go straight to the computer from the modem and try again (I've been this route about a dozen times with SBC/Yahoo DSL) and NO, I do NOT work for them, LOL.
If it still doesn't work, then call again, describe your problem and if the person is clueless, ask for a supervisor and BE STUBBORN. Keep insisting on a supervisor. If they tell you one is not available but will call you back, tell them fine, hang up and CALL BACK and insist again (you will most likely end up in a different call center). Keep being a pest.
It WILL get solved if you are the *squeaky wheel*. Liz