Transmission Slip Out Of Gear problems of the 2012 Hyundai Sonata

On 09/22/13, I left for a 75 mile trip. When I first started my car that morning, I noticed it was moving sluggishly, but thought it was due to our overnight chilly temperatures. I drove the short distance to the interstate. As I attempted to merge onto the interstate, I had the most frightening experience of my life. I pressed on the accelerator to prepare to merge and discovered that I had practically no acceleration! my car got to between 5000 and 6000 rpms before it shifted out of first gear! at that point, I was going approximately 45 mph while trying to merge onto an interstate, in front of a semi that would not get over for me to merge. I literally had my accelerator pedal pushed to the floor, as the car again hit between 5000 and 6000 rpms to shift into second gear! I was able to eventually get my car to 65 and turn on the cruise control . I double checked to make sure I was in drive (rather than neutral or manual--no dashboard lights on). On occasion during that drive, I turned off the cruise and hit the accelerator to see if what I had experienced was a fluke¿it was not. My accelerator was literally mashed to the floor as my car¿s speed slowly lurched higher, while my rpms raised above 5000 before shifting to the next gear. Once I returned home, I turned off my car for a few minutes, before restarting the vehicle to test it. The transmission problem was gone (although I question whether my turbo is still working effectively, as it seems less responsive). Today, I took my car to the local car dealership to address the recent Sonata recall, and I also requested they examine my transmission, describing the above incident to them. I noted that other drivers mentioned that a ¿waste gate� issue appeared to be causing the shifting problems. They could find no problems and suggested I shifted into manual accidentally.