don't want customer to be able to select a shipping option

I want to have free shipping if the order is over $10 and a flat rate of $2.00 if order is under $10. I have flat rate enabled with a cost of $2.00 and I have free shipping enabled $10 min.

When the order is under $10 is shows correctly that there is a flat rate $2 for shipping, but if the order is over $10 it shows a radio button option so that they can choose a shipping method and since Flat rate is the default if they don’t realize to choose free shipping it will charge them $2.00 even if there order is over $10. Is it doing this because I have both shipping options enabled (flat rate AND free shipping). What can I do to accomplish this but not have an option for them to choose from if order is over $10.00.

http://wordpress.org/plugins/woocommerce/