Billed for a total month device subscription but contract only from 16th

I am very frustrated. I have sent Telkom numerous queries regarding my billing and received no feedback except that it will be directed to the correct department even though the billing department as emailed is the correct department for account queries according to me. I started a new contract at Telkom from 16/01/2019 but was invoiced for the device subscription from 01/01/2019. How can this be correct as I did not even have the device?? How can I be billed for something I did not have. I cannot see how it can be accurate to invoice a device for a total month if the contract only started 16/01/2019.