Kia Sportage key stuck in ignition?

[~~Addicted_to_lipgloss~~]

I have a Kia Sportage and the key won't come out of the ignition. It does turn and cuts the car off, but won't turn to turn the stereo off. I have to take the cable off of the battery terminal to get the key released. I think something is wrong with the tumblers in the ignition switch, but I am not a mechanic and the only thing I know how to do is change my brakes.

Does anyone have any idea what's causing this and how it can be fixed/how much it will cost??