Yes, you do. You remain in complete ownership of all your work. If you own an ISBN, it will be published by you. However, if you choose to avail of an ISBN owned by CinnamonTeal, it will be published by CinnamonTeal. In both cases, you continue to own the rights in your name and CinnamonTeal does not make any claim or restriction on the ownership of your work.
However, please do note that if you wish to be published by some other publisher, after already being published by us you need to inform us a month in advance so that we can remove your book from our listings. In case your book is published by another entity, we will insist that the new entity issue you another ISBN.