The 25-year-old completed a move to Paris Saint-Germain last month, after the French side paid his €222million release clause.
Bartomeu was left furious by the antics of Neymar and his father and agent Neymar Santos Sr., who was behind the move to Ligue 1.
“We made the mistake of trusting Neymar and his father too much,” Bartomeu said.
When an Instagram account posted Bartomeu’s quote, Neymar couldn’t help but respond in the comments section, saying: “This president is a joke”.
Neymar already has three goals and three assists in three league matches for the French giants so far.