I think you are saying you straightened the barrel but it bent back the way it was? What you'll have to do is bend the barrel past straight because the metal has a certain amount of spring back to it. Do it slowly and it may take several tries to get it back where it will stay straight. Like I said before, at this point you don't have much to loose with this barrel. With a little trial and error I bet you can get it back just as accurate as it was as long as there are no sharp kinks where it's bent.
You are saying bend it past Square shoot it and see if it'll go some what straight?btw the barrel is bent upwards.