I added a new credit card,set as default but the payment wasn't taken and the internet is now not wo

Hi Robyn
If you go back in your account, you must have a link to force the payment

source: https://fizz.ca/en/faq/how-do-i-update-my-payment-method-or-credit-card-information

If your payment method is working, but you got only a temporary problem
Access your plan, then your payment method. If you see the "Make payment now" button, click to make a manual payment and your service will be restored within 2 hours.

After the payment is received from Fizz allow up to 2 hours to reactivate the service, and restart your device

You can also contact customer support by chat, from 8 AM to 9 PM every day:

1- Connect to your Fizz account by clicking « Login » in the top right corner at fizz.ca
2- Any ad blockers in your browser should be disabled.
3- Click on this link: https://fizz.ca/en/faq/how-do-i-update-my-payment-method-or-credit-card-information
4- The green chat bubble should appear after a few seconds in the bottom right corner.

Your can also send a message via facebook messanger https://facebook.com/fizzca and click send a message (this is a bit slower)

I had LOTS of trouble when I received a new credit card (same number, different expiration date / CVV). It took Fizz three weeks to figure it out. They kept saying it's the bank's fault, but the bank confirmed TWICE that the error was not on their end. I ended up filing a complaint with the CCTS and Fizz finally found the source of the problem and fixed it.
Fizz even admitted their payment system was "sensitive".
In the meantime, maybe you can use a friend's credit card to pay for your service.