When taxi driver Ashley Gibbins called the helpline of NTL hoping to have broadband installed, he was told, that all its operators were busy right now, but if he cared to hold the line his call would be dealt with as soon as possible.

So Mr Gibbins held. And held. Then held some more. Eventually, after an hour, Mr Gibbins decided he had had enough. He put the phone down and decided to wreak revenge.

By chance, Mr Gibbins discovered he could alter NTL's recorded message, and after he'd tinkered with it people seeking help were met with something altogether more blunt.

"Hello, you are through to NTL customer services," they were told. "We don't give a fuck about you, basically, and we are not going to handle any of your complaints. Just fuck off and leave us alone. Get a life."

NTL did not see the funny side and called in the police. Magistrates in Teesside, however, may have had similar experience on corporate helplines themselves.

Mr Gibbins, 26, from Redcar, Cleveland, was acquitted at Teesside magistrates' court on Tuesday of an offence under the Communications Act 2003 of making a grossly offensive message.

The magistrates decided Mr Cleveland's rant was merely offensive, and did not make the "grossly offensive" standard required for prosecution.

A spokeswoman for Cleveland Crown Prosecution Service said Mr Gibbins admitted he had left the message but denied it was grossly offensive.

"He did accept that he was responsible. The main question was whether the message was deemed to be offensive or grossly offensive.

"The judiciary heard all the issues before them and they decided in this particular instance that it was not grossly offensive," said the spokeswoman.

NTL's media centre put the Guardian on hold, suggested we try another number and then declined to comment.