Last week, Cuban offered Trump $1 million to the charity of his choice if he shaved his head.
On Monday, Trump told his Twitter followers that "Dummy @mcuban is at it again trying to use me to get publicity for himself!"
When Cuban challenged Trump to match his own $1 million to the victims of Superstorm Sandy, Trump fired back.
"Only 1 mill. dollars @mcuban? Offer me real money and I’d consider it. Your team and networks lose so much money I doubt you have much left!" the Donald tweeted. "When Apprentice became the #1 show on tv you tried copying me with The Benefactor- a complete and total ratings disaster for @ABC."
Cuban replied: "Have you seen #SharkTank ratings vs yr show ? But hey , feel free to live in the past :) ... Your command of TV facts is right up there with your command of political facts.."