Trump argues that his fund-raising was ‘done legally,’ in response to a Times investigation.

Former President Donald J. Trump on Monday responded to a New York Times investigation revealing that his re-election operation had refunded more than 10 percent of what it had raised online — $122 million of $1.2 billion — and that a flood of refunds had come after his campaign set up weekly recurring donations by default for online donors. Contributors had to uncheck a box to opt out, and the box became increasingly hard to find as his campaign’s financial struggles grew.

“Our fundraising efforts, working together with the Republican party, were all done legally,” Mr. Trump said in a statement.

The Times reported that many donors had unwittingly become repeat contributors to Mr. Trump’s campaign because of the prechecked boxes. Retirees, military veterans, nurses and political operatives were among those ensnared. Many complained to their credit card companies and banks that they had been victims of fraud.

Records show that the Trump operation refunded 10.7 percent of what it raised in 2020 on the digital donation-processing site WinRed, compared with a 2.2 percent refund rate for President Biden’s operation on ActBlue, the Democratic platform.

Mr. Trump, who did not rebut any of the figures in the article, focused on a different number, arguing that his campaign’s “dispute rate” — the tally of formal complaints to credit cards — had been less than 1 percent of transactions. “A very low number,” he said.

That would still represent about 200,000 disputed donations, which his campaign had previously said added up to $19.7 million.

Mr. Trump’s campaign has previously declined to say if the former president personally knew about the prechecked box scheme, and he did not speak to that in his statement. But he did not denounce the tactics.

“Before our two campaigns, 2016 and 2020, Republicans would always lose small dollar donations,” Mr. Trump said in his statement. “Now we win, or do very well, because we are the Party of Working Americans, and we beat the Democrats at their own game. We learned from liberal ActBlue — and now we’re better than they are!”