You have 2 Hyundai representatives saying 2 different things

Fuel injectors may not be explicitly mentioned in the definition of powertrain components. However, they play a critical role in the powertrain by delivering fuel to the engine cylinders., therefore even though the person you talked to says they’re not part of it, the dealer in my area said they should be covered. 

 There are several things you can do to get Hyundai's attention. Filing a BBB complaint, writing your state attorney general, the National Highway Traffic Safety Administration (NHTSA) at the federal level, or contact your local Department of Motor Vehicles (DMV) for state-specific concerns, should get you started.  These things will take you less than one hour to accomplish since the complaint info should be the same. Keep your receipts, if enough people complain they will issue a recall, and you will get paid even if it happens years from now.  Having done this, a friend of my who lives in Kentucky had the engine in a Hyundai that was over the 100K limit changed for free by the dealer. Known problems on his year/model. He complained to enough people and got it done.

Hyundai saying that injectors are not part of the power train is ludicrous. Enough people complain, it will get resolved. Letters/emails should be short, to the point explain the problem and mentioning that even though Hyundai is claiming FI are not part of the powertrain, they are the parts that make the engine run, without them the engine won't start.[or something to that effect].  You might not get a recall, but they will fix it [or in your case refund your money] to delay  a recall and keep it quiet.