key will not turn anti theft light flashing on dash

Get the car towed back to the dealership, it sounds as if your anti- theft system needs to be reflashed

Possible dumb question here, but could your steering wheel be turned putting pressure against the lock pin in the ignition? Have you tried turning the key while pulling downward on the left and right side of the wheel to relieve pressure while trying to turn the key at the same time? I am sure that would have nothing to do with the light but I would think you should be able to use the car with a valet key, and most anti theft systems don't "lock out" tghe ignition from being turned by the key, only keep and unprogramed key from starting it.