I found two magazine subscriptions on my iPad that I did not order. I clicked on one of them thinking that I could delete it from my playlist but it downloaded instead

If you've subscribed to them then you should be able to stop them auto-renewing - there are instructions on this page for managing and stopping auto-renewing subscriptions : Manage your auto-renewing subscriptions.

I did this but I want to get a refund. Is this possible?

Purchases are considered final but you can try the 'report a problem' page to contact iTunes Support and see if they will refund or credit you : http://reportaproblem.apple.com

Or you can try contacting iTunes Support via this page : http://www.apple.com/support/itunes/contact/