The Frenchman moved to the Nou Camp for a €120 million fee, signing a lucrative five-year contract with the La Liga champions.
However, Atletico are believe they are owed a further €100m, alleging that negotiations between Griezmann and the Catalan club first took place before the release clause lowered on July 1.
Atletico released a club statement which read:
‘Atletico Madrid believes that the amount deposited €120m is insufficient to meet his rescission clause, since it’s obvious that the commitment of the player and Barcelona was closed before the aforementioned clause was reduced from €200m to €120m.
‘Atletico Madrid believes the termination of the contract occurred before the end of last season due to events, acts and demonstrations carried out by the player and that is why we’ve already started procedures considered appropriate to defend our rights and legitimate interests.’
Griezmann’s lawyer, Sevan Karian, has revealed the World Cup winner is opposed to the way his former club have responded since the move was confirmed on Friday.
‘Antoine is very disappointed with the attitude shown by Atletico and the club’s hierarchy,’ he told L’Equipe.
‘They are acting in bad faith and are communicating the opposite of what they told him in person.
‘But let them do as they see fit, we will do the same if necessary. For the moment, for (Griezmann), he only wants to think about this new chapter in his career.
‘He wants to celebrate this weekend by discovering his new home.’