The phone bill was for more than $600 for calls her son had placed to adult entertainment 800 numbers. Aren’t 800 or 888 prefixes supposed to be toll-free? How can that be possible?

Technically, it’s true that you don’t have to pay for the phone call but you can be charged for the goods or services you agree to purchase during the call.

Here’s how it works. You respond to an ad in a newspaper for a free call to a horoscope service. Once on the line, you’re told there is a charge for information. On the spot, you’re given a PIN number and charges are billed to your phone number. Subsequent calls can be charged by giving the PIN number. That’s how an 800 or 888 number can be transformed into a very expensive pay- per-call service. Most of the complaints we receive are about adult entertainment lines and horoscope providers.

You can fight back. Bell Atlantic offers a service that allows you to block up to 20 different prefixes. There is a small charge, but it may be worth it.