a couple of things.
a) do not post in the forum AND send an email via the contact form with the same question. Once is enough.
b) your site/cart (you should have put a link to it in the post above) seems to work just fine from what i can see. If it still does not work, you have to give me a link to the pages where it does not and tell what i should be doing to reproduce this
c) i do not know what you mean by “WordPress Service Url”