Seller won't combine shipping, even though he's supposed to.

I recently made a purchase, which the item(s) descriptions say 2.99, + free postage thereafter. I made the purchases, the total seperated postage totalled to about 21 dollars (7 items).. I send a request for combined shipping, and I get it combined to 21 dollars, which was the original amount anyway. It's been 4 days, and I refuse to pay because I haven't had a response after that email (I've been sending 1 a day), and I also fear I'm to recieve a warning/flag for not paying. What should I do?|||Pay up, or face an unpaid item strike, its up to you.|||Your seller has their phone number in their listings, call them and discuss the matter and get the corrected invoice.|||No! Don't pay until he corrects it. You will not be penalized, just make sure to respond to any dispute with the facts.|||You have a phone number - call the seller!