How can I recycle the items in storage when it is full?

Hi, many of us have the same concern as you. Unfortunately there is currently no way to take back something you've put up for sale. Your only options are 1) pay 1 sim cash to delete an item, in which case you lose it and get no money back, or 2) have a friend buy it from you, and then you can buy it back. Hopefully the dev's will put that option in for a future update.