One time I placed a token bid on some camera gear; nothing serious, just making sure it didn't go for a song. I was at the grocery store when the auction ended and my wife--bless her--put in a winning bid on my behalf. When I got home she told me the good news: that I had won an auction for more money than I wanted to spend and for a camera I didn't really need. We're talking sixty bucks so it was a cheap lesson to learn. Now I tell her in advance the ones I am serious about and the ones I am just placing token bids on.
Hope it all works out on your end. Most sellers have been reasonable with me whenever there have been issues. Since you've bought from them before I would expect they will understand your plight and refund your money in good faith.