I think you misread something. The "few million" do not refer to the 900M but instead to the interest on the loan which is actually "a few" (less than 10) million.

There's a 1.8 billion loan outstanding, split between several lenders. Citi accidentally paid half of that loan back to some of the lenders, transferring 900 million. All the lenders but one returned the payment, leaving 176 million in dispute.

So, Citi did make a 900 million dollar blunder, as the headline says, but the subject of the story is that remaining 176 million. It's a misleading headline, not because it's not true, but because it doesn't describe the subject of the article.

That's pretty close to how much it is. $172 million and change. The $900m figure was the total amount sent, all but the $172m has been returned, at least according to the article.