RescueTime Lite has a 3 month report history limit. You agreed to the RescueTime TOS Terms of Service when you signed up, and that included the stipulation that you only get 3 months of data with the free plan. That's clearly on the subscription page:
That's legal. They can charge you for access to more than 3 months of data in the form of a longer subscription. You're not being asked to pay to access your data; you agreed to a free plan that included limited access to that data.
And this is part of what you "signed" as a click-wrap contract that is relevant to your dispute:
...You understand and agree that the cancellation of your membership or a
particular component of the Service is your sole right and remedy with
respect to any dispute with RescueTime. This includes, but is not
limited to, any dispute related to or arising out of: (a) any term of
the TOS or RescueTime’s enforcement or application of the TOS; (b) any
policy or practice of RescueTime, including the Privacy Policy, or
RescueTime’s enforcement or application of these policies; (c) the
data available through the Service; (d) your ability to access and use
the Service; or (e) the amount or type of fees, surcharges, applicable
taxes, and any RescueTime billing methods. RescueTime, in its sole
discretion, may terminate your membership and remove and discard any
of your Recommendations without notice if RescueTime believes that you
have violated or acted inconsistently with the TOS. RescueTime will
not be liable to you for termination of your membership to the
Service....
You only recourse in a dispute with them is to stop using the service. (Also see Are terms of service legal contracts? )
And RescueTime retains all rights to your data. It might be the data that you contributed to the service, but you granted them a permanent license to use it.
The license granted in these TOS does not constitute a transfer or
sale of RescueTime’s ownership rights in the RescueTime Database.
RescueTime retains all right, title, and interest in and to the
RescueTime Database including all related intellectual property
rights.