Unfortunately, brake calipers are not covered under the Kia warranty unless the failure of the component was due to a manufacturer defect.
Kia generally chalks up caliper damage or malfunction to normal wear and tear, so unless the calipers are cracked or warped in a fashion that’s only synonymous with faulty manufacturing, you’ll probably have to pay out of pocket for these repairs. Fixing or repairing a brake caliper is typically between $250 and $600 per wheel.