I can not make a call and my friends can not call me too

You need to buy minutes when you quit unlimited plan
https://fizz.ca/en/faq/what-is-an-add-on-and-how-do-i-buy-one
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Wallet
https://fizz.ca/en/faq/how-do-i-add-funds-to-my-fizz-wallet
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Read point 3 of this link
https://fizz.ca/en/faq/abcs-fizz-mobile-services
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If is not working contact the support to know what happen with your plan plan
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CHAT
Go to this page https://fizz.ca/en/faq/resolving-issues, if you are not connect login
The business hours: every day from 8 a.m. to 9 p.m. (EST).
Wait 5 seconds for the bubble icon to appear at the bottom right of the browser and click on the icon to chat with support. Try a different browser if you have issues getting the bubble to appear.
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.
 
FACEBOOK
Your can also send a message via facebook messanger https://facebook.com/fizzca and click send a message (this is a bit slower)
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CONTACT FORM
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.

Tan,
You need to buy add-on (calls) if you want be able to use your phone now.
Are you sure it's a good move to have eliminate the option of unlimited calls in your plan?
If your needs are minimum for the calls, it's OK.
Think about that.

To add money to your wallet or buy an add-on you must click on "my plans" and then "manage my plan", you will find there all your options. I have never bought minutes add-ons, but I can tell you about the wallet. It costs 0,05$ by text and 0,3$ by call minute.

Did you block each others numbers?