Pre-order and cancel Avengers - trz beta?

This week the beta for Avengers starts, which only pre-orders can use. I'm still not sure if I'm buying the game, so I wanted to use the beta as a kind of demo for me.

Can I pre-order the game, then cancel it straight away and still get the beta key? If so, in the Psn store, on Amazon, or somewhere else?

As far as I know there's also an open beta for everyone without a pre-order. This should be available on PS4 from August 14th.