how can I fix my cassette player in my 2003 Buick Regal?

How can I fix my cassette player in my 2003 Buick Regal? The display shows the comment "tape in" even though there is no tape inserted. If I put a tape partially in and press eject, the player "pulls in" the cassette, clicks, then within seconds ejects it again - but the display still says tape in". Please help!