i bought a similar one from homedepot, they didn't produce any seeds before they died.
You might try asking at The Seed Saving Forum, even though you did not see any seeds on yours. Some seeds can be quite tiny and obscure.
btw...if you are the one starting a thread and would like to make a clickable link (like I did below), first type your message, and hit Preview You will then see the Optional Link URL box along with the Name of the Link URL. Just copy the URL into the top box and make up a name for the link, and preview again, and lastly submit.
Here is a link that might be useful: