How can I access file stored with Tradebit ??

Please help... I would like to edit the file I uploaded and is now stored with Tradebit. I am the original author and should be able to access it to make some changes to it (corrections). I have not been able to do that. Can someone please tell me how to access the file ? My emails to Tradebit are not answered. Thank you.

Make the changes to the file you have on your computer. Use FTP to upload the updated file to TradeBit. Go into your power admin for the listing you want to update. Click the Update with Upload link towards the top of the listing editor. Choose your updated file. Save your listing.