Automatic Renewal - Changing the Messaging Plan

I currently have a GoPhone and am doing the automatic renewal feature for 1000 messages at $9.99/month.  I notice that the unused messages roll over every month since the package is automatically renewed every 30 days.  

If I wanted to change the package from 1000 messages/month (with automatic renewal) to 200 messages/month (with automatic renewal), would I lose all the text messages I have accumulated up to this point?

Thanks!