Good evening, how do I pause the execution of if in javascript?

In the loop we use break. I tried adding a return shortly after the alert (which I will show in the following code) but it gives a reload on the page, I do not know why ...

if (cookie == 1) {
    alert("Oi, você enviou uma mensagem a pouco tempo, em breve vamos te responder, ok?");
    return;
}

The cookie variable is created above, but it does not matter if you post the cookie here.

Reinforcing my problem once more, I want to pause the execution of this if and exit, but a reload is happening this way and can not continue like this.

Complete code as requested:

if (document.querySelector('.menu-help-box-form')) {
    document.querySelector('.menu-help-box-form').addEventListener('submit', function (event) {

        var cookie = getCookieValue('form_help_box');

        if (cookie == 1) {
            alert("Oi, você enviou uma mensagem a pouco tempo, em breve vamos te responder, ok?");
            return;
        }

        event.preventDefault();
        var formD = new FormData(this);
        var helpBObject = {};
        var con = {
            0: "name",
            1: "email",
            2: "reason",
            3: "message"
        };
        var numCont = 0;

        formD.forEach(function (element) {
            helpBObject[con[numCont]] = element;
            numCont++;
        });

        $.ajax({
            url: "/api/dataentities/HB/documents",
            type: "POST",
            timeout: 0,
            headers: {
                "Content-Type": "application/json",
                "Accept": "application/vnd.vtex.ds.v10+json"
            },
            data: JSON.stringify(helpBObject),
            success: function () {
                document.querySelector('.success-send-form-help').style.display = "flex";
                var d = new Date();
                d.setTime(d.getTime() + (1 * 24 * 60 * 60 * 1000));
                var expires = "expires=" + d.toUTCString();
                document.cookie = "form_help_box=1; " + expires + "; path=/";
            },
            error: function (error) {
                console.log("Erro Help Box: ", error);
            }
        });
    });

    document.querySelector('.cancel-send-form-help').addEventListener('click', function () {
        document.querySelector('.menu-help-box-form').style.display = "none";
        if (document.querySelector('.success-send-form-help')) {
            document.querySelector('.success-send-form-help').style.display = "none";
        }
        document.querySelector('.menu-help-box-ul').style.display = "block";
    });
}

Edited to complement

If the cookie exists (condition passed in if), I want it not to execute whatever is below that if.