License doesn't work - Request of Chargeback

In December I got a monthly license of Adobe Connect Learning to provide a training session in Jan-06th.  Unfortunately, after creating the virtual session and sending the invite to our contacts, last Friday, as I tried to view how my presentation would be shown, appeared a message about “user limit exceeded”, but there was no one connected besides me. I’ve tried a lot of changes in my access to correct this situation but anything worked. I also tried to contact Adobe by mail asking for help but no reply. So I would like an information about how can I cancel my account and how can I have a chargeback, as the only reason I bought the license with this specific session and it didn’t work. Hope have any answer now. Regards