Check engine light

What is your question?

The check engine light came on on my 2011 ct200h Monday. I took it to the dealership and the code that came up was p0301, misfire cylinder one. They replaced the engine coil and spark plugs. 2 days after the light came on again. Took it back and the same code came up. I'm working all weekend and didn't have time to leave my car, and need my car to get to work. I plan on bringing it back Monday am. Any recommendations? I paid $500 for the coil and new plugs, which seems overpriced to me. Anything I can do in the meantime? Any advice is greatly appreciated.

How long has your 2011 Lexus CT200h had this problem?

Less than 1week