Item not received when postage was agreed

[gdar8768]

I paid £120 online for an item which was advertised as to be collected. I e-mailed the seller to see if he would post it and he agreed to and I paid a furtehr £10+ for postage to him.  I had to give him the 'collect' code that I had received in order for him to be able to process the payment.  Since then the item has not been posted to me and the seller does not reply to my e-mails.  I can't start a refund claim because E-Bay thinks that I have collected the item, which I have not.  How can I get my money back, or have I been conned?

[plpmr]

Your only hope if to try your payment provider.

[gdar8768]

Thanks for the advice.  Is there no way to contact EBay about it?