Cesare Prandelli claims Valencia went back on their promise to reinforce the squad in January and has accused the club of being run by "numbers people" after walking away from Mestalla.
The Italian coach abruptly quit after three months in charge on Friday, leaving the team 17th in LaLiga and facing a desperate struggle to avoid the drop.
Senior club officials, speaking at a news conference on Saturday, accused the former Italy boss of "giving up and abandoning ship", only for Prandelli to hit back in his own media briefing shortly afterwards.
"I was promised that we were going to buy footballers," he said.