Code not being removed upon plugin deletion

I deactivated then deleted this Fastpring plugin from my site, but the code is still there slowing my website down (see below). How do I get rid of it?

/*! fastspring-builder 0.8.0 */

!function() {
“use strict”;
function a(a) {
if (void 0 === a || null === a)
return !0;
for (var b in a)
if (a.hasOwnProperty(b))
return !1;
return JSON.stringify(a) === JSON.stringify({})
}