Aluminum has a crystal structure and can be hardened using a process called "work hardening." Long story short, you've hardened your pole by causing dislocation movements in the crystal structure of the aluminum. If you compare your bent pole to your other poles, you'll notice that it doesn't flex as much as it used to, that is because it is now a harder alloy than the rest. Any attempt to bend it back now that you've somewhat work-hardened it will cause fractures in the alloy. The only way to soften the aluminum is to anneal it, which involves heating the aluminum almost to it's melting point and then letting it cool slowly, but if you try to do that then your pole will be so soft that it won't flex, it'll just bend like welding wire. You would have to know how to re-harden the aluminum after you annealed it and bent it back, not a simple process, and not that cheap to get a metal worker to do it for you.
You're best option is to either replace your pole, or deal with it being bent, unless you have a friend who is a millwright and knows how to anneal and harden alloys. Bent poles aren't that bad, I've been using bent poles in my MSR Hubba Hubba for years. Your pole is still strong, it's just not as straight and flexible as it used to be, annoying, but still functional.
You won't be able to get your pole back to what it was, but if you wanted to attempt to get your pole straight and see how much longer it lasts, my recommendation would be to use a pipe or tube straightener.
Just don't expect results, and expect a struggle, like I said, that hardened bend won't bend back easy, if you take the pole to a hardware store then you might find some plumber guy that'll be convinced he could get it straight for you. But don't be surprised after he breaks it or puts stretch fractures in it from trying. You can be surprised instead if he actually gets it straight and it doesn't bend right back the first time you try using it again.