Occasional Stuck Key in Ignition?

Bought this car used about four months. It had a number of issues about which almost all have been resolved. The remaining issue is that occasionally the key gets stuck in the ACC position after turning off the engine. Turning the ignition back to the on position (restarting the car) and shifting from Park to Drive and pushing the stick shift forcefully back into Park will sometimes allow me to turn the ignition switch into the Off position and I can pull the key out. Sometimes turning the steering wheel hard to the left or right will allow the ignition switch to turn to the off position and I can pull the key out. Other times, I have to insert a screwdriver into the Key Release hole in the bottom of the steering column.

I took the car to a Chevrolet dealership three months ago. Over $600 later, they did not diagnose either of the two problems that I took it in for (one of which was the stuck key in ignition) but gave me a $12K-plus list of recommended repairs. Another repair shop that I took it two could not get the problem to occur, even though they kept it and drove it for several days. By the way, after my initial discovery of the problem, I ordered new keys and had them cut by a locksmith. Still the problem persists.

Thank you for your assistance.