Fizz doesn't let me upgrade my internet speed.

Hi Kevin

this is the procedure

"Important – any change to your plan must be made 48 hours before the end of your payment cycle. During those 48 hours, systems are frozen and no change can be made. You’ll therefore have to wait for the next payment cycle."

source: https://fizz.ca/en/faq/i-would-like-to-change-my-fizz-home-internet-plan-how-do-i-do-this

However, you can try to contact the support, to see if they can do an exception

1- Click on this link: https://fizz.ca/en/faq/i-would-like-to-change-my-fizz-home-internet-plan-how-do-i-do-this
2- The green chat bubble with the ? should appear after a few seconds in the bottom right corner.
3- Click on it, and select chat if available, or any other option