Amazon gives non-Prime members free shipping at $35 or more of eligible items. Instead of simply letting users get the product with free shipping, they’ve added a discount that prices it exactly one cent below the $35 limit, while only subsidizing the price with $3.38, which is about half of what they’ll then charge you for shipping.
When I did this (I actually ended up not needing the item), they refunded the item minus the shipping cost, so…
When you choose the option of why you returned it, some include not covering the shipping cost.
Try choosing something else next time.