Account to what? Roku or some add-on service?
Roku accounts don't expire, and roku accounts don't even have your phone number in them, so there is no way for Roku to call you.
Did you by any chance call someone to set up your Roku originally? If so, that is a scam, and since the scammer has you phone number, they can call you back to try to scam you again whenever they choose. If this happened, your Roku might be connected to a roku account that the scammer created.
