Just want to make sure we are not talking about a Stronglight or a TA crank here - in which case you need to be sure you have the right tool.

If it is a Japanese crank with a universal puller and the threads are stripped - I would try the torch (Alum expands faster than steel), and pry it off from behind.

If there is something not allowing the tool to thread in, I'd try the LBS to see if they can chase the threads.