Ramos quit the Spanish club on Friday and was appointed as Martin Jol's successor at Spurs on Saturday evening.
He told the Sunday Express: "If Spurs wanted Ramos they had to speak to me, but they approached him directly.
"They have acted incorrectly and I shall report them to Fifa and Uefa to defend my rights."
Del Nido is not alone in his fury at the manner at which Spurs allegedly went about their business.
Leeds United chairman Ken Bates has also fumed at Tottenham after the way they have pursued assistant manager Gus Poyet.
"I was watching the Uefa Cup ties on Thursday when Sky told me my assistant manager was off to Spurs," he said.
"What's that all about?"