No, it's not. You made a very common mistake of taking the 'negation rule' too far.
Many learners memorize the rule as "Negation -> Genitive". It's not a surprise, because Accusative is a very common case, and then negated Genitive (also common) is still Genitive. But there is no such rule. The rule is "Negated Accusative -> Genitive". Other cases stay unchanged when negated.