I never place a automatic bidding but it was activated.

Question

woodland_gnome · Answer

ALL bids "activate" "automatic bidding." ANY bid is treated as a "maximum bid" under the automatic a/k/a proxy a/k/a incremental bidding system. It's not an option that you do something special to invoke or can even opt out of; it is simply HOW eBay auctions work (highest bidder wins, but price is calculated primarily from the maximum bid of the second highest bidder, and eBay hides the full amount of the leader's/winner's maximum bid to the extent it exceeds that calculated price). Even if you just bid the minimum, you can end up with a hidden maximum (if the prior leading bid is cancelled). The notion that eBay "automatically bids on your behalf" is an analogy to describe the process for those who want simple answers but results in many misunderstandings of what actually happens in particular situations (such as thinking there is a difference between "regular" and "automatic" bidding).

If you mean that you are now in the lead at a higher "current bid" than you intended to bid, you made a typo (most likely omitted the decimal divider). A typo in entering the bid amount is the ONLY bidder error that may be corrected by retracting the bid. You must rebid the correct amount (the amount you intended to type in the first place) immediately after the retraction goes through. There are time limits (12 hours before the scheduled auction end or 1 hour after the bid was placed, whichever is later, but in no case later than the actual end of the auction) so don't delay.
https://www.ebay.com/bfl/retractbid