The CIN spokesman said the album had slipped passed officials into the classical chart by mistake.
The classically trained foursome went to number two in the classical charts last week with their debut album, Born.
They have since been blacklisted by chart chiefs the Chart Information Network (CIN), after they met to discuss the band's record.
He added their music was not "really a classical idiom" because of the use of dance beats.
"There's a classical supervisory committee and they felt it more of a pop record than a classical record," he said.
The CIN's guidelines say that, to qualify for the classical charts, at least half of the music on an album must be written by a known classical composer.
Bond say they bring classical sounds up to date, with tinges of everything from trance and house music to Salsa and traditional East European folk songs.
Haylie Ecker, 24, of Bond, said: "In a modern world it is disappointing that the classical elite cannot embrace change."
Unconventional
Bond's album was released almost two weeks ago. It went to number 36 in the contemporary music charts and just missed the top spot in the classical charts.
The CIN spokesman said the album had slipped passed officials into the classical chart by mistake.
They had been late in obtaining a copy of the album and did not have time to assess it properly, he said.
"It was on the Universal Classics label and shops like HMV were racking it up in their classical department, so we thought we had better err on the side of allowing it in," explained the spokesman.
The four Bond women are Australians Haylie Ecker from Perth and Tania Davis from Sydney, Eos Chater comes from Cardiff, Wales, and Gay-Yee Westerhoff on cello originates from Hull.
They were brought together by Mel Bush who guided the career of smash hit violinist Vanessa-Mae.
The foursome adopt a purposefully modern image, wearing daring clothes and posing in bikinis - rather than donning the usually sober attire of the classical world.
Ecker said: "We have a poetic licence to entertain people all around the globe, which is what our album Born does - it is a classical musical mixture of sounds and rhythms from around the world."