Athlete David Bedford tried to derail the relaunch of a directory enquiries advert on Tuesday night.
118 118 runners go detective for new advert
The Number, which runs the 118 118 service, was threatened with legal action by him last year for ads which featured 1970s-style runners.
A new campaign will see the pair pose as detectives from the same era dressed in tight yellow jumpsuits.
Mr Bedford and five models circled the building in outfits promoting BT's rival service, 118 500.
It was part of a satirical publicity stunt by the former 10,000 metre record holder, who claims The Number based the ads on him but did not pay him.
Leaflets were handed out saying: "Dave Bedford wishes to point out that he does not endorse the 118 118 product and personally uses the rival 118 500 service delivered by BT.
"He believes that for both value and service they, like himself, are the original and the best."
Mr Bedford said: "This is a peaceful protest. You will know I don't see eye-to-eye with 118 118."
The Number denied the new ads were prompted by the threat of legal action by Mr Bedford.
He claimed the company "stole" his image from the 1970s.
Ofcom, the communications regulator, ruled in January that the 118 runners with their droopy moustaches and red socks, sky-blue shorts and hooped tops were a "caricature" of Mr Bedford.
The regulator found at that time that The Number had been in breach of the UK's Advertising Standards Code - but declined to impose a ban on the advert.
A spokesman for The Number said: "The new image has nothing to do with David Bedford.
"It has been in development for six months, plus there are no restrictions on what we can do with our advertising".
The 118 118 twins will keep their moustaches in the new adverts, which appear on 12 March, but their long hair has been "restyled" and is shorter.
In the campaign they cruise the streets in an orange three-wheeled car, offering help to people.
The new adverts are part of a £10m campaign to promote additional services from The Number, such as unlimited enquiries and cinema listings.
The service, which launched in the UK on 10 December 2002 has around 50% of the UK directory enquiries market.