On May 3 (of 2010), I bought the wrong thing on eBay. It's a case of mistaken identity, where I watched two cards and ultimately bought one thinking I had the other. Thousands of transactions since 1996 and I can still push the wrong "Buy It Now" button!
The seller advertised a 7-day return window, so I confirmed his policy by email, repackaged the "wrong" card, and dropped it in the mailbox with money for return postage.
On June 1, I emailed to confirm receipt of the exchanged card, since it'd been a couple of weeks. The seller said it arrived OK, but that he was out of country until mid-June. If needed, he could tell his office to send it ASAP.
"No problem," I said, "and no rush. Just send it once you're back." And waited.
Being June 24th, it's been 7 weeks since the original purchase for under $10, and I assume it'll take another reminder email (and waiting into July) at this point.
So today's poll question: What's your "longest" eBay transaction, at least for something that wrapped up successfully? Weeks? Months? A year?