Here is the link to one of the other threads about the issue

https://community.ebay.com.au/t5/Technical-Issues/Bid-Retraction-not-working-2-days-so-far/m-p/24653...

If you wish to talk to eBay, you need to go to 'eBay Help' at the top of the page and scroll through the options to find the one best suited to you, the follow the prompts from there