How can I change my plan, if I can't get nobody on the phone?

Unfortunately, we do not have phone support. The best way to contact us is here in the Support Forum or you can email us at support@jotform.com. 

To change your subscription plan, you can downgrade your account or upgrade your account. Here are the guides that can help:

https://www.jotform.com/help/331-How-to-Upgrade-My-Account

https://www.jotform.com/help/341-How-to-Cancel-a-Subscription-and-Downgrade-Back-to-Free

I hope this information helps. Thank you.