Login your account and go to "My orders". Check if the item status has been changed from "Shipped" to "Delivered".

If "Delivered", there will be a button under it that says "Return". Click it and it will guide you to return the item. You will have option whether to return for exchange, store credit or full refund.

Sometimes, your item status is not updated to "Delivered" yet. So, there will be no "Return" button to click. In that case, scroll down on any Lazada page, at the bottom left there are 2 links that say "Contact us here" and "send your request here". Click on either and make your request for refund there. They will get back to you and help you process your refund.

Either way, unfortunately, you need to cover for the return cost.

I have returned an item before which Lazada said they will refund the shipping cost of returning the item to my bank account. But it's been a month now but they didn't credit the shipping cost to me even though they have refund the item to credit card.

3 weeks ago, I received one faulty item priced RM18 which I bought at RM10 because I used RM8 off voucher code. But I didn't return it though because it wasn't worth just to get RM3-4 back after the shipping cost and the trouble to queue at the Post Office.

Hope this help.