There are several ways you can get a bang without chopping off your hair, this girl below in the video for example did it by swept the front section of her hair to the side.
I came up with an insane way to do it. You will need some straight hair weaving in your hair color (100% human hair works the best, if you can't find exactly your color you can always dye it) and a headband. First you cut three 3'' wide sections, glue them on top of one another. Next you cut the hair to about 4''-5'' long and curl the hair inward using an curling iron.
Finally glue the hair to the center under the headband. When you want to get the pin-up look, just curl your hair first and put the headband on. My hair is not curly right now, so I don't have a good photo to put here (I will as soon as my hair is curly again). Of course you can do many other kinds of bangs (side-swept bang, emo bang, 80's claw bang, etc) like this, since one package of weaving has a lot of hair, you can make several bangs with one package. It's cheaper than getting a haircut and you can do a different look everyday without commitment.