Santos say Robinho's personal demands were simply too rich for them to cover.
"The decision is definitive, unless something changes on the other side," President Luis Alvaro de Oliveira Ribeiro told Radio Bandeirantes.
"Milan finished up at a pretty reasonable price-tag, less than 6m. Everyone knows what he wants to earn and we have to respect that.
"However, what Robinho wants to earn coupled with what the club would've paid Milan creates a figure that is implausible for any Brazilian club."