Welcome! How can I help with your Hyundai...

Dear sir 
Thank you for contacting us 
First about the remote key , yes you can replace and reprogram it at keys specialist  .
Second about the AC switch it still working on when you switch the car on and the AC vent is on or it on first or second or third or fourth speed .
And if it still working although every switch is off ,  also it should be replaced by a electrican and and that maybe needs to change the whole AC panel.