If at any point during your Trial or Premium account, your website contains 100 subpages or less (and you only have 1 domain), it is possible to get back on the Free subscription. Unfortunately, we are unable to downgrade your existing account, but you can follow the steps below:
This account will be a Free subscription for as long as your page count does not increase above the 100. If you do this within the 30-days Trial period, there will be no cost to you.
See also Why does your scanner say that my website has more than 100 pages?