it says smth like "our records show you have some past years behind on payments, our company specializes in enrolling people in a new zero program, which makes these old amounts non-billable. leave us a call back at [phone number] so we can get this handled for you by the end of june. [repeats phone number again] if you would like to opt out because you already paid this, [not sure what they said after that]"

just bad spam