Why can’t I add my card in payment method?

I received an email from Fizz about updating my credit card in the payment method. I didn’t do anything about my account.But the system of fizz deleted the only card in my payment method. After that I can’t add another one (that’s reached card limit ). I changed every credit card I have, even tried to use another computer but it’s doesn’t work. Now fizz lock my mobile support since I cannot make the payment . Fizz really should find a better way for their service. Would I lose my phone number?