paying using debit card for item purchased on ebay.

[jcmoore-rainbow]

I purchased a high heel shoes on ebay on Friday, 7 March 2014.  I thought I have paid it already by clicking pay now, and entering my name and my debit card number, and at the bottom I click payment processed by paypal.  But they sent me an invoice so this means I still have to pay for it, and when I tried to pay for it, it keep asking me for my email address and I keep entering it, but it keep saying to me we can't find your email address. I keep trying but still it didn't go.  Can you help me?