In 3:169 Allah makes it clear that those who die in His way are alive, and they receive sustenance from their Lord. When we say Ya Ali Madad, we are basically asking the Imam to help us with sustenance God has given him, just like you ask your friend or neighbor for help since God has given them some sustenance or power in this world.
The verse you quoted is addressing pagans who would worship idols and call out to them. Idols are not alive nor do they have sustenance from their Lord, nor is anything besides Allah to be worshipped.