Correction is "아니에요". In Korean, "~예요." is not almost used. But ~예요 is shortly version ~이에요. 아니 + 에요 (O) 아니 + 이에요(예요) (X) example) 갈 것이에요 (O) -> 갈 거예요(O)

The exception to the rule occurs when used with names, and likely where we get confused: 이에요 comes after a syllable ending with 받침 예요 comes after a syllable ending without 받침 제씨 예요. (For a man it's best to say 제씨 입니다.) 김 이에요. ...and 아니예요 is grammatically incorrect.