For Standard Accounts, your account is enabled for SMS, Voice, PhoneID, App Verify, and Score by default, so you should be able to use these at any time. If you attempt to access any other products you will get the message you are seeing.
For Enterprise Accounts, make sure that the product you are trying to access is enabled for your account and that you are currently contracted to use this service.
Please note that there is a difference between 'SMS' and 'SMS Verify', and 'Voice' and 'Voice Verify'.
If the above information doesn't apply, please contact Support so we can double check that your account has the right settings.