You can't just magically change your ending date when people have already bid on the item. Part of the reason for end dates is to allow users to keep an eye on an auction, and bid at the last minute if they want to.
The only time that you can change an end date is if there are no bids.
The user has 48 hours from his post, as per your previous conditions to either be outbid (which could be 25,010tc) or come up with the withdraw fee. If the user is not outbid, he must pay 20%, which is 5000tc. If they are unable to do so, their account will be penalized and suspended.
In the meantime, White_roses, you've received infraction posts multiple posts and illegal bumping. I don't see how you can whine about other users not following rules when you won't follow them yourself.