I had a problem similar to this.
I sold a bed on ebay. I specified that it was collection only, or I could deliver in the local area for a small fee.
I specifically stated that I would not send the bed with a courier or post it under any circumstances.
Someone bid and won it and then sent me a message asking for my address and when would be a good time for collection, I told the buyer when I would be in and sent my address.
The buyer then arranged a courier without telling me. I refused to giver the courier the bed (although he said he couldn't take it without it being packaged up anyway)
The buyer went mad at me when I emailed to tell him that the bed was collection only and that I would not accept responsibility for a courier.
He then suggested that I deliver the bed to him, since he had already paid for his courier he expected the bed delivering.
He was completely unreasonable and refused to accept that the item was collection only.
In the end I realised I had two options. Not send the bed, and get the bed feedback, strike against my account and pay the fees while issuing a refund.
Or send him an invoice for postage and packing, organise a courier myself and send the bed securely with proof of postage.
I did the latter, but it wasn't easy as he refused to pay P&P, insisting that it was my responsibility on that he had already paid one courier.
Ebay told him if he wanted the item sent via courier he had to pay P&P fees, which he eventually did, the postage cost him over £60, and I charged £30 for packaging and effort. :D
He did try to file a significantly not as described dispute against me later on, claiming that the bed was in an 'unusable condition' but thankfully I always take pictures of items before sending them so he didn't win.