Del Nido said: "They will get the response they deserve from Seville.
"We will channel our energy, force and all the means available to us into making sure Tottenham pay the consequences of a situation they have illegally and illegitimately provoked."
Tottenham approached Ramos twice - first in August when they went behind ex-boss Martin Jol's back, and again last week when they convinced him to join.
Furious Del Nido added: "Here in Spain we're not used to treachery between professional football clubs. You'll see what we do with regard to Fifa."