The star, who was involved in the latest remake of Do They Know It’s Christmas?, posted a message on Twitter in which she said lyrics she and African artist Angelique Kidjo recorded did not make the final cut.
The song became the fastest-selling single of the year after just a day’s sales following its release last week.
However, there have been complaints over the song’s content, with some of the lyrics changed to reflect the ebola crisis in West Africa.
Various critics claimed the charity single was offensive and reinforced negative stereotypes of Africa.
Sande tweeted: “I agree the lyric needs changing. In fact, I feel a whole new song is required. Angelique Kidjo and I made and sang our own edits. Unfortunately, none of these made the final cut.
“Aside from my feeling regarding the lyric, there was no doubt in my mind or heart that this project came from a place of pure and respectful intent. Sir Geldof made this clear when he addressed us all: I haven’t heard a man speak with such passion and sincerity in many years.
“The response from world governments has been horribly slow and media coverage has been minimal though thousands and thousands are dying.
“The sole objective is to raise awareness and money to provide medical aid to those suffering the ebola outbreak.”
The reworked version of Do They Know It’s Christmas? features stars including One Direction, Bono, and Ellie Goulding, and is expected to raise millions to help fight the ebola crisis, which continues to grip parts of the continent.
British chancellor George Osborne agreed to waive Vat on the single’s sales, so every penny will help the charity effort.
Just spoke to the remarkable Bob Geldof. Told him we'll waive VAT on #BandAid30 so every penny goes to fight Ebola— George Osborne (@George_Osborne) November 15, 2014
The new recording marks the 30th anniversary of the song, which was originally put together to raise funds for famine relief in Ethiopia.
Meanwhile, singer Lily Allen has said she turned down the opportunity to be on the new version.
She told the Mail on Sunday: “I got an email asking me to do it. It’s difficult to explain why I didn’t do it without sounding like a complete shit. I prefer to do my charitable bit by donating actual money and not being lumped in a with a bunch of people like that.
“It’s like the success club and I’m not really in that club. I don’t think I’m above it all — I’m way below it. But there’s something a bit smug about it.”