It is currently not possible to delete items completely from Sellery. If you wish to remove a live listing from Amazon, you can either:
1. Set that item to a quantity of zero in Sellery and Sellery will then delist that item from Amazon. This option will ONLY work if the item is Merchant Fulfilled and Sellery's inventory management features are enabled as well as your account set to 'on' under Settings > Accounts.
2. Create a smart list that contains the item(s) you wish to remove. Go to Settings > Pricing Overview and map that smart list to 'do not list' at the very top of your overview. This option will work for Merchant Fulfilled listings as long as Sellery's inventory management features are enabled.
3. If Sellery's inventory management features are disabled, simply remove the listing from you Amazon Seller Central account and Sellery will set any inactive items to a quantity of zero when it next updates your inventory.
4. Any changes to FBA listings must be done directly on Amazon Seller Central (or another 3rd party application) and Sellery will import those changes every 6 hours.