Cobrajet,
In the name of "better customer service," computer vendors are becoming more and more invasive. "It's for your own good." The reality is that they're just getting tired of trying to educate the consumer, so they're finding ways of fixing problems while letting users stay uninformed. (That's to say, back in "the day," if you had a problem, by the time you were done fixing it, you knew all about why it happened, how to prevent it, more about your computer, etc. Not anymore.)
How old is your laptop? Was it physically disconnected from the line? Just because your modem makes a racket when you tell it to dial up, doesn't mean it has to; it's just a speaker on/off setting in the modem preferences, and that could easily be changed and then changed back without you knowing it.
As for knowing your phone number, if your computer already had a connection up, the phone number is irrelevant; the IP number (your computer's address on the internet at that moment) would be more useful, but it's even more likely that your computer (if it's new-ish) has some way of uniquely identifying itself to Dell no matter where it is, using some sort of broadcast signalling.
"Microsoft has your best interests at heart" is flase for two reasons: can anyone name them?
Steve
'01 Kaiser Silver #1027, Chicago
"I figure 'Overkill' is ju-u-u-ust about enough"