Telkom WiFi Router problem

I have a problem, i have contract with Telkom i should be receiving 20G day and 20GNight But i have been receiving 10G . On the 1st August i logged in my account i see i had 10G i called their head office at 9:00 am to ask why i have 10G not 20G they told me that my phone might have ran updated. i issue is my phone can not use 10g to update so i told them i use WiFi at work everyday and my phone only updates on the 1st of every month. i have been struggling with them since i had this contract. can you please assist.