Charlie, 15, and 13-year-old Leondre were hailed as favourites in this year's competition after judge Simon Cowell hit the golden buzzer for the pair and they made it all the way to the final show, before being placed third.
Speaking to This Morning on Friday, they said they are so grateful to Cowell - who has now signed them to his music label - for his support.
"He has given us such an amazing opportunity," said Leondre. "I mean, our single is coming out on Sunday, that's absolutely amazing, I can't believe it."
Charlie added: "It's phenomenal how he's given us this life changing opportunity, if it wasn't for him we wouldn't be where we are today so we are so thankful towards him."
Since the BGT final, where the boys sang their own version of Hopeful by Twista and Faith Evans, they have been kept very busy with their music and plans for the future.
Charlie explained: "We've just finished out school and radio tour, which was really fun, we got to go to loads of different schools all around the country and then we've got our signing tour next week to sign copies of the single.
"And then we've got concerts (coming up) so we are very busy.
"We've also been recording and thinking of some new ideas, but it's all a secret at the moment, all kept on the down low," he joked.
Bars & Melody have a huge following in the UK since their appearance on BGT, but they also gained a fan in US comedienne Ellen DeGeneres, who invited them to appear on her show in LA.
The boys performed for her US audience and told the talk show host about their experiences since appearing on the UK programme.
"Ellen has been really, really supportive of us," Charlie told This Morning.
"She always tweets about us and hopefully we'll get to go back (to LA) to see her soon."