I have a very weird situation going on, and Im wondering if it can be a syntax or placement error, something a new beginner like me isnt aware of. Any advice is much appreciated!

It's the code below. In function o() I'm trying to removeEventListener that calls the function s() from a button which is stored in variable t, and addEventListener that calls the function c() instead. I use the same syntax for adding and removing EventListener in both functions; function c() used to work. Function o() does not work, and returns "Argument 2 of EventTarget.removeEventListener is not an object". In o() function I'm unable to use the removeEventListener and addEventListener, it gives me the same error, whatever I try. When I put them in a function and called a function within o(), it worked, but wrongly, and pretty much broke the functionality.
Code:
o = function(e) {
            for (var i = document.getElementsByClassName("choices"), s = 0; s < i.length; s++) i[s].removeEventListener("click", o);
            t.removeEventListener("click", s, !1), t.addEventListener("click", c, !1), e.target.innerHTML == sequence[15] ? (this.style.backgroundColor = "#cafc6c",
                n.innerHTML = "Correct answer", r.score += 3, console.log(r.score)) : (n.innerHTML = "Wrong, it is "
            + sequence[15], this.style.backgroundColor = "#dd2179"), t.disabled = !1;
},
c = function() {
            i.innerHTML = "The 2nd part of the test is done.", n.innerHTML = "You got " + r.score + " points in this part.",
            e.innerHTML = "", window.Test.updateController(r.score), t.removeEventListener("click", s, !1), t.addEventListener("click", window.Test.nextStep, !1);
};