Fibre Upgrade

I have requested upgrade since September from 399 to 799 for my wifi. I spoke to an agent on whatsapp and confirmed that request have been made and I will receive confirmation email but it was never done. I requested it again last month. On the 2 December i had 400 on my account and they did not debit and my Wifi was off, so i assumed that the upgrade was done so i made EFT payment of 799. The invoice they sent shows 399. When I ask for clarity on whatsapp the agent said the upgrade was not made. This is very frustrating as I am using this wifi for work purposes and the upgrade is required by the company.