I’m afraid there’s not much hope for it. đ I looked a little online, and as cheap as that lens is, it’s not worth it to have it repaired. Here’s a link with some methods for testing whether your IS is indeed working or not: https://www.flickr.com/groups/556573@N24/discuss/72157622976369887/
Here’s where you can buy a replacement for a decent price: https://www.keh.com/shop/canon-ef-s-18-55mm-f-3-5-5-6-is-zoom-lens-118941.html