Yes you can
You need to contact the support
The funds you put in your Wallet can be refunded to you. You must make your request during our business hours using the chat bubble located in the lower right-hand corner of this page.
To contact the support you need to go to this page https://fizz.ca/en/contact-us, Fizz push you to find your solution, therefore, you need to search in the solution hub to your solution and only after 10 seconds that you are in a solution page Fizz will give you the chat bubble.
If the chat bubble does not appear, this means that the number of sessions waiting for our answers surpasses our processing capacity. If that happens, send us a private message via Facebook Messenger or Twitter.
Your can also send a message via facebook messanger https://facebook.com/fizzca and click send a message (this is a bit slower)
You can also fill a contact form from your account Once logged in, from the account panel go to My Profile → Contact Form (the subject are limited) and fill out the form and someone will email you back.
oups, little mistake!
As Mike suggests, contact Fizz support and see if they can credit it to your account some other way (or reverse that charge).