Shipping settings using fixed rate and USPS

In Settings – Store – Shipping I am using the fixed rate setting for the option for a “Pickup” and a $0 charge. I am also using the USPS setting for calculating cost if not a pickup. Everything works great but I am having issues where customers put in a zip code to calculate shipping but then the default radio button is for “Pickup” – $0. If they don’t manually click on the radio button for the shipping charge, it doesn’t get added to their bill.

So my question is, is there a way to make the “Pickup” option disappear or not be an option when they calculate a zip code for the shipping charge? Or just to make the default be the shipping charge and force them to change it to Pickup if they need to?

The website is http://sweettherapychocolates.com/

Thanks for any help you can give.

Bryan