In the business, they call it slamming: switching phone companies on you without your OK.

It's a trick that's about as old as the deregulation of the phone business and it happened to Neil Pelzer of Greeley.

Pelzer discovered that his phone bill had gone up by $5 a month.

Pelzer said he mostly uses his phone line to connect his computer to the Internet.

It's a simple hookup: A local call from an unpublished number and no need for long distance service.

For his long distance, he has a cell phone.

But the mysterious $5 charge was for a connection to MCI WorldCom, a long distance connection he didn't want.

A Qwest customer service rep told him that his number had been "slammed" and Pelzer said he wasn't going to pay the $5. He said the Qwest rep told him that they'd take him off but he would then have to pay $5.30 a month.

Pelzer wonders how someone tagged his unpublished number and, without his knowledge or permission, messed with his phone service.

Not legal, and not uncommon either, said Call7 For Help's Bill Clarke.

But Pelzer may be stuck with a $5 a month connection tab even though he has no long distance connection.

Qwest is allowed to stick that fee on your monthly bill just in case you make a long distance call, Call7 For Help reported.