Pas de Problème :
Don’t you just hate it when people say ‘Not a problem’ when they have been causing you problems large and small for several months? Naming no names but there is a person like this in my (working) life now. I would remain more polite if they would just stop saying ‘Pas de problème !/ not a problem!’, even if a full-blown apology (des excuses épanouies) is beyond them.