What to do when an eBay seller does not send you an invoice?

I bought this thing from eBay last night that was listed as Buy It Now . It said on the description that the shipping was $10. However after buying it, when i went to check out, the shipping field was blank and eBay asked to ask for an invoice from the seller. I did so but have not gotten any reply yet. I also emailed him personally again just to make sureWhat should i do? Wait? Complain to eBay?