What make & model of Roku TV do you have? I'd guess its flash memory somehow became corrupted, but have never encountered this before, even after years of abruptly powering down various Roku's.
You won't have to pay for anything again, though, only re-enter your account details for whatever services you subscribe to (or re-register using a computer browser or phone for those that allow this). A big hassle to be sure, but no monetary loss, at least!
