Ebay can be annoying. I bought a ring several years ago. Nobody had bid on it at all. After I bid, another bidder started bidding as well. They kept bidding until they were the top bidder, and I stopped bidding (ran the bid up about $50 - $75 extra).
Just before the auction ended, their bid was withdrawn, and I wound up as the winner. Now keep in mind, only their last bid was withdrawn so I still had to pay the highest I had bid. In my opinion it was shill bidding. If they were going to allow them to withdraw their bid, ALL of their bids should have been withdrawn leaving me to pay the original price.
I contacted ebay and told them exactly what had happened step by step. They pretty much told me that they saw nothing wrong with the auction.
I took the ring, but I've wished several times that I had taken it further and requested that my bid be withdrawn as well - just as a matter of principle.
I stopped using ebay years ago after similar things happened to me before. I was buying charms for a charm bracelet- well these little things are worth about $3/each at any store you go to. They were selling for 25-50 cents so I bid on a couple. It used to be that if you entered a price, it assumed it was dollars if you didn't put in a decimal. Now it assumes cents. I meant to put in 16 cents and put in $16 by mistake! Since then they have a price confirmation and all of that. Well ONE person basically sat there and bid up the price until I paid over $15 for a stupid bead. It was one of dozens the seller was selling at the same time, all going for around a quarter. The same person was trying to bid up all of them. I know some sellers at least used to do that to bid up their own items. Currently they are out protecting buyers, but it's because sellers also had some good years of screwing the buyers over. The pendulum will swing back again eventually.
