Unable to cancel order as a buyer

[tomsk3000]

I bid on an auction listing. I then realised the item was not an original but a modern reproduction (listed in the wrong category).  As the auction had less than 10 hours to run I was unable to retract my bid.  I therefore contacted the seller and explained the situation.  The seller was happy to remove the bid but was unclear of the process.

Later when I checked my ebay, I noticed that there was a request to complete payemt for the item?  I am unable to cancel this order and the seller does not know what to do.

I do not blame the seller, as I appreciate how complicated ebay can be, especially for fairly new sellers.  I would just like to know how is it possible for a bid on an auction listing to be converted into a 'buy it now' bid without the buyers consent?  Surely the software should have inbuilt protection against this happening?

[ruby*tuesday]

Advise the Seller to go to More Actions to the Right of the Item on his Sold Page and find Cancel selecting "Buyer Requested Cancellation." His Final Value Fees will be Credited back to his Seller Account. 

[tomsk3000]

Thanks I have forwarded this advice to the seller. Hopefully this will remedy the issue with this particular listing, but I still don't understand how it was possible. At no stage did I agree to a buy-it-now option.