Can't change contact form background

For some reason, I cannot change the image I placed on the contact form page. I am using contact 7 and placing it into my contact page. I placed an image as a background and have tried numerous times to swap it out for a new one, but to no avail. I have deleted cache and even removed the image altogether, but it is still showing. Can someone help me?

http://beyondyourgardengate.com/contact/

Thanks!
ame